As stated in the Preface, the purpose of this work is the
standardization of colors and color nomenclature, so that naturalists
or others who may have occasion to write or speak of colors may do so
with the certainty that there need be no question as to what particular
tint, shade, or degree of grayness, of any color or hue is meant.
Therefore, it is unnecessary to treat of the subject from any other
point of view; it will be sufficient to say that this work is based
on a thorough study of the subject from every standpoint, and that
practically all authoritative works on the subject of color have been
carefully consulted.[2]
PLAN. —The scientific arrangement of colors in this work is based
essentially on the suggestions of Professor J. H. Pillsbury for a
scheme of color standards,[3] which have also been the basis of several
other efforts toward the same end, as the plates in Milton Bradley's
"Elementary Color" and educational colored papers, Prang's charts of
standard colors, Klinkseick and Valette's "Code des Couleurs," etc.;
but while all these present a scientifically arranged color-scheme and
more or less adequate number of colors they all fail to supply a ready
or convenient means of identifying and designating the colors—the
principal utility of a work of this kind. It is in the latter respect
that the present work is believed to meet, more nearly than any other
at least, this essential requirement, and in this consists whatever
originality may be claimed for it.
The "key" to the classification or arrangement herewith presented is,
of course, the solar spectrum, with its six fundamental colors and
intermediate hues, augmented by the series of hues connecting violet
with red, which the spectrum fails to show. If, with the red-violets
and violet-reds thus added to the spectrum hues, the band forming
this scale be joined end to end a circle is formed in which there is
continuously a gradual change of hue, step by step, from red through
orange-red and red-orange to orange; orange through yellow-orange and
orange-yellow to yellow; yellow through green-yellow and yellow-green
to green; green through blue-green and green-blue to blue; blue through
violet-blue and blue-violet to violet; and violet through red-violet
and violet-red to red—the starting-point—with intermediate connecting
hues. In the solar spectrum, both prismatic and grating, but especially
the former, the spaces between the adjoining distinct colors are very
unequal; therefore for the present purpose an ideal scale must be
constructed, so that an approximately equal number of equally distinct
connecting hues shall be shown. Distinctions of hue appreciable to the
normal eye are so very numerous[4] that the criterion of convenience
or practicability must determine the number of segments into which the
ideal chromatic scale or circle may be divided in order to best serve
the purpose in view. Careful experiment seems to have demonstrated
that thirty-six is the practicable limit, and accordingly that number
has been adopted.[5] If the number of intermediate hues were equal
in all cases there would, in this scheme, be five between each two
adjacent fundamental colors of the spectrum; but a greater number of
recognizably distinct hues is obviously necessary in some cases than in
others; for example, spectrum orange is decidedly nearer in hue to red
than to yellow, and therefore the number of intermediates required on
each side of the orange is different, being in the proportion of four
for the red-orange series to five for the orange-yellow, and similarly
six are required for the violet-red series, while four suffice for the
blue-violet hues.
There is no known means by which we can measure the proportion of
two or more _pigments_ in any given mixture, "because color-effect
cannot be measured by the pint of mixed paint or the ounce of dry
pigment;"[6] but, fortunately, we have a very exact method, in the
color-wheel and Maxwell disks, by which the relative proportions of
two or more _colors_ in any mixture may be precisely measured. This
method has been used in the painting of every one of the 1115 colors
of the present work, by means of one disk to represent each one of the
thirty-six colors (both pure and "broken"), together with a black, a
white, and a neutral gray disk, the last being a match in color to
the gray resulting from the mixture of red, green and violet on the
color-wheel;[7] the neutral gray disk, however, being used only for
the making of disks for the broken series of colors (′, ′′, ′′′, ′′′′,
and ′′′′′) and for the scale of neutral grays (Plate LIII.) These
colored disks are slit on one side from center to circumference, and
therefore by interlocking two or more they may be adjusted so that
either occupies any desired percentage of the whole area, which may be
very precisely determined by a scale of 100 segments shown on the outer
edge of a larger disk on which the colored disks are superimposed. When
connected with the color-wheel and adjusted as may be desired, and then
rapidly revolved, the two or more distinct colors resolve themselves
into a single uniform composite color, whose elements are shown, in
their relative proportion, by the scale surrounding the disks.[8]
The scales (both horizontal and vertical) of the present work are
all prepared directly from definite color-wheel formulæ, based on
carefully calculated curves; the thirty-six pure spectrum hues,
represented by the middle horizontal line of color-squares on Plates
I-XII (together with an equal number of intermediates represented by
blank spaces), requiring a separate curve and consequently different
relative proportions of the two component colors for each series
of hues—that is, the series from red to orange, orange to yellow,
yellow to green, green to blue, blue to violet, and violet to red,
respectively; but the progressive increments of white in the scales
of tints, black in those of shades, and neutral gray in the several
series of broken colors are exactly the same in every case. The first
series of Plates (I-XII) shows the pure, full spectrum colors and
intermediate hues (middle horizontal line, nos. 1-72),[9] each with its
vertical scale of tints (upward, _a-g_) and shades (downward, _h-n_),
the increments of white for the tints being 9.5, 22.5, and 45 per
cent., respectively, those of black in the shades being 45, 70.5, and
87.5 per cent. The remaining Plates show these same thirty-six colors
or hues in exactly the same order and similarly modified (vertically)
by precisely the same progressive increments of white (upward) and
black (downward), but all the colors are dulled by admixture of neutral
gray; the first series (1′-72′, Plates XIII-XXVI) containing 32 per
cent. of neutral gray, the second (1′′-72′′, Plates XXVII-XXXVIII) 58
per cent., the third (1′′′-72′′′, Plates XXXIX-XLIV) 77 per cent.,
and the fourth (1′′′′-72′′′′, Plates XLV-L) 90 per cent. The last
three Plates (LI-LIII) show the six spectrum colors[10] (also purple,
the intermediate between violet and red) still further dulled by
admixture of 95.5 per cent. of neutral gray, these being in reality
colored grays; to which are added a scale of neutral gray and one of
carbon gray, the former being the gray resulting from mixture of the
three primary colors (red 32, green 42, violet 26 per cent., which in
relative darkness equals black 79.5, white 20.5 per cent.); the latter
being the gray produced by mixture of lamp black and Chinese white, and
the scale a reproduction of that in the author's first "Nomenclature of
Colors" (1886, Plate II, nos. 2-10). It should be emphasized that in
all cases except the scale of carbon grays, only the disks representing
the middle horizontal series of colors (both pure and broken) have been
used, in combination with a black and a white disk, respectively, to
make the colors of the vertical scales of tints and shades.
The coloring of a satisfactory set of disks to represent the thirty-six
pure spectrum colors and hues was a matter of extreme difficulty, many
hundreds having been painted and discarded before the desired result
was achieved. Several serious problems were involved, the matter of
change of hue through chemical reaction of the combined pigments or
dyes[11] (especially the latter) being almost as troublesome as that
of securing the proper degree of difference between each adjoining
pair of hues. The method by which satisfactory results were finally
secured was as follows: First, six disks were colored to represent
each of the fundamental spectrum colors, according to the author's
conception of them.[12] These six disks were then placed against a
suitable background (a neutral gray), in spectrum sequence, with wide
intervals for the accommodation of connecting series of disks, which
were then colored so as to represent an apparently even transition
from one to the other. When this very difficult task had been done as
well as the eye alone could judge, each intermediate was then measured
on the color-wheel and the relative proportions (in percentages) of
its two component colors recorded. After this had been done for all
the intermediate hues each series (the red-orange, orange-yellow,
yellow-green, green-blue, blue-violet, and violet-red) was taken
separately and a curve constructed on cross-section paper from the
recorded ratios. These curves were found to be in all cases more or
less irregular or unsymmetrical, but nevertheless were sufficiently
near correct to serve as a basis for a symmetrical curve; and after the
points out of proper line were suitably relocated the two component
colors were correspondingly readjusted on the color-wheel and each
faulty disk corrected (or a new one painted) until it exactly matched
the required combination. The scales representing the tints and shades
of each color, and also the gray or broken colors were similarly
determined by corrected curves.[13]
By the method adopted of running each of the thirty-six spectrum hues
through a scale of tints and shades, and repeating the combination
through several series modified by increasing increments of neutral
gray, practically the entire possible range of color variation is
covered,[14] rendering it an easy matter to locate in the plates,
either among the colors actually shown or in an intermediate space,
any color which it is desired to match; and where short distinctive
names have not been found (their place being, tentatively, supplied by
compound names), as, necessarily, must often be the case, any color
or intermediate between any two colors, either as to hue, tint, or
shade, may be readily designated by the very simple system of symbols
(numerals and letters) employed.[15]
In order to designate any color for which a satisfactory name cannot
be found, or one not represented on the plates, it is only necessary
to proceed as follows: Suppose the color in question is nearest 1 on
Plate I; say, for example, is intermediate in hue between 1 (spectrum
red) and 3 (scarlet-red), or in other words if represented in color its
position would be in the uncolored space designated as no. 2; and in
tone between the full color (middle horizontal line) and tint _b_. Its
designation, therefore, is _2a_. Exactly the same method applies to any
of the other blank spaces, as well as to the colors themselves, except
that in case of the broken colors the "primes" (′, ′′, ′′′, ′′′′, or
′′′′′) are to be affixed to the hue number. First locate the _hue_,
designated by number, then the _tone_, designated by lower case letter,
the full, pure colors of the middle horizontal row being designated by
number alone.
Color Names.—While it is true that the naming of colors as usually
employed has so little to do with the purely technical aspects of
chromatology or color-physics that, as Von Bezold remarks[16] "we are
in reality dealing with the peculiarities of language," it is equally
true that a collection of color standards designed expressly for the
purpose of identifying and designating particular colors can best
attain this object by the use of a carefully selected nomenclature.
In other words, the prime necessity is to standardize both colors and
color names, by elimination of the element of "personal equation"
in the matter. In no other way can agreement be reached as to the
distinction between "violet" and "purple," two color names quite
generally used interchangeably or synonymously but in reality belonging
to quite distinct hues, or that any other color name can be definitely
fixed. Various methods of handling the matter of color in zoological
and botanical descriptions, etc., by the avoidance of color names and
substitution therefor of symbols, numerals, or mechanical contrivances
(as color-wheel and spectrum analyses, color-spheres, etc.) have been
devised but all have been found impracticable or unsatisfactory.
The author has taken the trouble to get an expression of opinion in
this matter from many naturalists and others, and the preference for
color-names very greatly predominates; consequently, whenever it has
been possible to find a name which seems suitable for any color in
this work it has been done, leaving as few as possible unnamed, and
for these some other means must be devised for their designation. (See
page 8). The selection of appropriate names for the colors depicted on
the Plates has been in some cases a matter of considerable difficulty.
With regard to certain ones it may appear that the names adopted are
not entirely satisfactory; but, to forestall such criticism, it may be
explained that the purpose of these Plates is not to show the color
of the particular objects or substances which the names suggest, but
to provide appropriate, or at least approximately appropriate, names
for the colors which it has seemed desirable to represent. In other
words, certain colors are selected for illustration, for which names
must be provided; and when names that are exclusively pertinent or
otherwise entirely satisfactory are not at hand, they must be looked
up or invented. It should also be borne in mind that almost any object
or substance varies more or less in color; and that therefore if
the "orange," "lemon," "chestnut" or "lilac" of the Plates does not
exactly match in color the particular orange, lemon, chestnut or lilac
which one may compare it with, it may (in fact does) correspond with
other specimens. Without standardization, even if arbitrary, color
nomenclature must, necessarily, remain in its present condition of
absolute chaos. Even the standard pigments are not constant in color,
practically every one of them being subject to more or less variation
in hue or tone, different samples from the same manufacturer sometimes
varying to the extent of several tones or hues of the present work;
indeed, in every case where two or more samples of the same color
have been compared it has been found that no two are exactly alike,
the difference often being very great. For example: Of five samples
of "vandyke brown" only two are approximately similar, each of the
other three being widely different, not only from one another but from
the other two, one being a blackish brown, another reddish brown, the
third a yellowish orange-brown. Of eleven samples of "olive" no two
are closely similar, the color ranging from a shade of dull (grayish)
blue-green to orange-brown, dark brownish gray, and light yellowish
olive; and the same or nearly the same degree of variation is seen
in absolutely every color examined, showing very clearly the utter
worthlessness of color names unless fixed or standardized.
In order to obtain as many color names as possible for standardization
it has been necessary to draw from all available sources. Several
thousand samples of named colors have therefore been collected, and
for convenience of reference and comparison gummed to card catalogue
cards, with the name, source, and other data thereon. These include
the colors from many standard works, among them Werner's "Nomenclature
of Colours" (Syme's edition, 1821), Hay's "Nomenclature of Colours"
(1846), Ridgway's "Nomenclature of Colors" (1886), Saccardo's
"Chromataxia" (1891), Mathews' "Chart of Correct Colors of Flowers"
(American Florist, 1891), Willson and Calkins' "Familiar Colors,"
Oberthur and Dauthenay's "Repertoire des Couleurs" (1905), Leidel's
"Hints on Tints" (1893), "Lefévré's Matieres Colorantes Artificiales"
(1896), the Standard Dictionary chart of "typical colors," the
educational colored papers of Milton Bradley and Prang, and many
others; and besides these practically all of the artists' oil, water,
and dry colors, manufactured by Winsor and Newton, F. Schoenfeld and
Co., Charles Roberson and Co., George Rowney and Co., Madderton and
Co., R. Ackermann and Co., Bourgeois, Binant, Chenal, Le Franc, Devoe,
Raynolds, Osborne, Bradley, Hatfield and others; also the coal-tar or
aniline dyes of Dr. G. Grübler & Co., Continental Color and Chemical
Co., and Henry Heil Chemical Co., and the well known Diamond Dyes;
chromo-lithographic inks, embroidery silks, etc., etc.
The material from which to select suitable color names was greatly
augmented, almost at the last moment, from two sources, as follows: (1)
A very large collection of color-samples (unfortunately mostly unnamed)
collected and mounted on cards by Mr. Frederick A. Wampole, a talented
young artist, to whom was delegated, by a Committee of the American
Mycological Society, the task of preparing a nomenclature of colors
based upon spectroscopic determinations, but which, unfortunately,
the untimely death of Mr. Wampole prevented from progressing beyond
the accumulation of this collection. For the use of this material I
am indebted to the courtesy of Dr. Frederick V. Coville, Botanist of
the U. S. Department of Agriculture, and Mr. P. L. Ricker, Assistant
Botanist, Bureau of Plant Industry, in the same Department. (2) A
splendid collection of colored Japanese silks, taffetas, velvets, and
other dress goods, kindly sent me by Mr. C. H. Hospital, of the silk
department of the firm of Woodward and Lothrop, Washington, D. C. The
very large number of colors represented in this collection are all
named and have afforded a considerable number of the names adopted in
the present work.
For obvious reasons it has, of course, been necessary to ignore many
trade names, through which the popular nomenclature of colors has
become involved in really chaotic confusion rendered more confounded
by the continual coinage of new names, many of them synonymous and
most of them vague and variable in their application. Most of them
are invented, apparently without care or judgment, by the dyer or
manufacturer of fabrics, and are as capricious in their meaning as in
their origin; for example: Such fanciful names as "zulu," "serpent
green," "baby blue," "new old rose," "London smoke," etc., and such
nonsensical names as "ashes of roses" and "elephant's breath." An
inspection of the sample books of manufacturers of fancy goods (such
as embroidery silks and crewels, ribbons, velvets, and other dress-
and upholstery-goods) is sufficient not only to illustrate the
above observations, but to show also the absolute want of system or
classification and the general unavailability of these trade names for
adoption in a practical color nomenclature. This is very unfortunate,
since many of these trade names have the merit of brevity and euphony
and lack only the quality of stability.
It has been difficult for the author to decide whether the standards
of his original "Nomenclature of Colors" (1886) should be retained
in the present work. Some of them are admittedly wrong (indeed,
certain ones are not as they were intended to be); besides, owing to
the method of reproducing the originals (hand stenciling) there is
considerable variation in different copies of the book, one or more
reprints, necessitating new mixtures of pigments, adding to this lack
of uniformity.[17] Many persons, however, have urged the retention of
the old standards, on the ground that they have been used by so many
zoologists and botanists in their writings during the last twenty-five
years that they have become established through common usage. This
very important consideration has induced the author to retain such of
the old standards as can be matched in the present work, even though
some of them do not agree strictly with either his own or the usual
conception of the colors in question. An asterisk (*) preceding a color
name indicates that the name in question is adopted from the older
work, the variation between different copies of the work requiring
the selection, in the new one, of a color representing as nearly as
possible an average of the former.
In any systematically arranged scheme, unless the number of colors
shown is practically unlimited, it will, necessarily, be impossible
to find represented thereon a certain proportion of colors comprised
among even a very limited number selected at random, or only roughly
classified. Hence many (thirty-six, or more than five per cent.) of the
colors shown in the old "Nomenclature of Colors" fall into the blank
intervals of the present work, being intermediate either in hue or
tone, or chroma, sometimes all. It is necessary of course to provide
some means for the correlation of these with the present scheme, which
is done by the list on page 41, where the position of each is shown.
The question of giving representations of metallic colors in this
work was at one time considered; but the idea was abandoned for the
reason that these are in reality only ordinary colors reflected from
a metallic or burnished surface, or appearing as if so reflected; the
actual hue is precisely the same, though often changeable according to
angle of impact of the light rays, and relative position of the eye,
this changeableness being sometimes due to interference.[18] Colors
again vary, without actual difference of hue, in regard to quality of
texture or surface; that is to say, the color may be quite lustreless,
appearing on a dull, sometimes velvety surface, while again it may be
more or less glossy, even to the degree of appearing as if varnished.
To deal with these variations, however, requires simply the use of
suitable adjectives. For example: To indicate a color which has no
lustre or brightness, the adjective matt (or mat) may be used, in
preference to _dull_, which implies reduction in purity or chroma;
other adjectives, appropriate in special cases, being velvety, glossy,
burnished metallic, matt-metallic, etc.
Color Terms.—No other person has presented so forcibly the urgent need
for reform in popular nomenclature nor stated so clearly and concisely
its shortcomings and the simple remedy, as Mr. Milton Bradley, from
one of whose educational pamphlets on the subject[19] the following is
quoted: "The list of words now employed to express qualities or degrees
of color is very small, in fact a half dozen comprise the more common
terms, and these are pressed into service on all occasions, and in such
varied relations that they not only fail to express anything definite
but constantly contradict themselves.... Tint, Hue and Shade are
employed so loosely by the public generally, even by those people who
claim to use English correctly, that neither word has a very definite
meaning, although each is capable of being as accurately used as any
other word in our every day vocabulary"....
Certainly one would expect that men of learning, at least, would employ
the broader color terms correctly; but some of the highest authorities
on color-physics habitually use them interchangeably, as if they were
quite synonymous; and even the dictionaries, with few exceptions, give
incorrect or "hazy" definitions of these terms. It is not strictly
correct to say a "dark tint" or "light shade" of any color, because a
_tint_ implies a color _paler_ than the full color, while a shade means
exactly the opposite; and to say an "orange shade (or tint) of red,"
a "greenish shade (or tint) of blue," a "bluish shade (or tint) of
violet," etc., is an absurdity, for the term _hue_, which specifically
and alone refers to relative position in the spectrum scale, without
reference to lightness or darkness, is the only one which can correctly
be used in such cases.
Indeed the standardization of color terms is almost if not quite
as important, in the interest of educational progress, as that of
the colors themselves and their names; therefore, to make easy a
clear understanding of the specific meaning of each, the following
definitions are given:—
_Color._—The term of widest application, being the only one which can
be used to cover the entire range of chromatic manifestation; that is
to say, the spectrum colors (together with those between violet and
red, not shown in the spectrum) with all their innumerable variations
of luminosity, mixture, etc. In a more restricted sense, applied to the
six distinct spectrum colors (red, orange, yellow, green, blue, and
violet), which are sometimes distinguished as _fundamental colors_ or
_spectrum colors_.
_Hue._—While often used interchangeably or synonymously with color,
the term _hue_ is more properly restricted by special application
to those lying between any contiguous pair of spectrum colors (also
between violet and purple and between purple and red); as an orange
_hue_ (not shade or tint, as so often incorrectly said) of red; a
yellow _hue_ of orange; a greenish _hue_ of yellow; a bluish _hue_ of
green; a violet _hue_ of blue, etc.
_Tint._—Any color (pure or broken) weakened by high illumination or
(in the case of pigments) by admixture of white, or (in the case of
dyes or washes) by excess of aqueous or other liquid medium; as, a
deep, medium, light, pale or delicate (pallid) _tint_ of red. The term
cannot correctly be used in any other sense.
_Shade._—Any color (pure or broken) darkened by shadow or (in the case
of pigments) by admixture of black; exactly the opposite of _tint_; as
a medium, dark, or very dark (dusky) _shade_ of red.
_Tone._—"Each step in a color scale is a tone of that color."[20]
The term tone cannot, however, be properly applied to a step in the
spectrum scale, in which each contiguous pair of the six distinct
spectrum or "fundamental" _colors_ are connected by _hues_. Hence
_tone_[21] is exclusively applicable to the steps in a scale of
a single color or hue, comprising the full color (in the center)
and graduated tints and shades leading off therefrom in opposite
directions; or of neutral gray similarly graduated in tone from the
darkest shade to the palest tint. Each one of the colored blocks in the
vertical scales of the plates in this work represents a separate tone
of that color.
_Scale._—A linear series of colors showing a gradual transition from
one to another, or a similar series of tones of one color. The first
is a _chromatic scale_[22] (or scale of colors and hues) and in the
plates of this work is represented by each horizontal series; the
second is a _tone scale_, on the plates running vertically, growing
from the full color, in the center, to a pale tint (at the top) and
a dark shade (at the bottom). For clearer comprehension of these
two distinct scales, each plate of this work may be compared to a
sheet of woven fabric; the chromatic scale (horizontal) representing
the warp, the luminosity or tone scale (vertical) the woof. A third
kind of color scale is represented by adding progressive increments
of neutral gray to any color. This is shown by the several series
of Plates, of which the first (Plates I-XII, with colors numbered
1-71) represents each step in the spectrum scale unmixed with gray,
followed by five other series in which the same colors[23] are shown
dulled by gradually increasing increments of neutral gray, the first
(Plates XIII-XXVI, colors 1′-71′) containing 32 per cent., the second
(Plates XXVII-XXXVIII, colors 1′′-71′′) 58 per cent., the third (Plates
XXXIX-XLIV, colors 1′′′-69′′′) 77 per cent., the fourth (Plates XLV-L,
colors 1′′′′-69′′′′) 90 per cent., and the fifth (Plates LI-LIII,
colors 1′′′′′, 15′′′′′, 23′′′′′, 35′′′′′, 49′′′′′, 59′′′′′ and 67′′′′′)
95.5 per cent. of gray, the last being in reality colored grays.
Finally scales are shown (on Plate LIII) of neutral gray (in which
all trace of color is wanting), and of carbon gray, a simple mixture
of lamp-black and chinese white. It is not easy to find a suitable
name for these scales of reduced or "broken" colors, but they may, for
present convenience, be termed _reduced_ or _broken scales_.
_Full Color._—A color corresponding in intensity with its
manifestation in the solar spectrum.
_Pure Color._—A color corresponding in purity with (or, in the case of
material colors, closely approximating to) one of the spectrum colors.
_Broken Color._—Any one of the spectrum colors or hues dulled or
reduced in purity by admixture (in any proportion) of neutral gray, or
varying relative proportions of both black and white; also produced
by admixture of certain spectrum colors, as red with green, orange
with blue, yellow with violet, etc. These broken colors are far more
numerous in Nature than the pure spectrum colors, and include the
almost infinite variations of brown, russet, citrine, olive, drab, etc.
They are often called dull or neutral colors.
_Fundamental Colors._—The six psychologically distinct colors of the
solar spectrum; Red, Orange, Yellow, Green, Blue, and Violet.
_Primary Colors._—Theoretically, any of the spectrum colors which
cannot be made by mixture of two other colors. According to the
generally accepted Young-Helmholtz theory, the primary colors are
red, green, and violet: orange and yellow resulting from a mixture of
red and green, and blue from a mixture of green and violet. There is
considerable difference of opinion, however, as to this question, and
further investigation of the subject seems to be required; at any rate,
authorities fail to explain why red may be exactly reproduced (except
as to the degree of luminosity) by a mixture of orange and violet,
exactly as yellow results from mixture of red and green or blue from
green or violet, green being, in fact, the only spectrum color that
cannot be made by mixture of other colors.[24]
_Chroma._—Degree of freedom from white light; purity, intensity or
fullness of color.
_Luminosity._—Degree of brightness or clearness. The relative
luminosity of the spectrum colors is as follows: [Yellow (brightest)?],
orange yellow; orange; greenish-yellow, yellow-green, and green;
orange-red; red and blue (equal); violet-blue, blue-violet, violet.[25]
_Warm Colors._—The colors nearer the red end of the spectrum or those
of longer wave-lengths (red, orange, and yellow, and connecting hues)
"and combinations in which they predominate."[26]
_Cool, or Cold, Colors._—The colors nearer the violet end of
the spectrum or those of shorter wave-length, especially blue and
green-blue. "But it is, perhaps, questionable whether green and violet
may be termed either warm or cool."
_Complementary Color._—"As white light is the sum of all color, if
we take from white light a given color the remaining color is the
complement of the given color." When any two colors or hues which when
combined in proper proportion on the color-wheel produce, by rotation,
neutral gray, these two colors each represent the complementary of the
other.
_Constants of Color._—The constants of color are numbers which measure
(1) the wave-length, (2) the chroma, and (3) the luminosity.
In addition to the terms defined above there are many others, for which
the reader is referred to the chapter on "Color Definitions" on pages
23-30 of Milton Bradley's excellent and most useful book "Elementary
Color."
TABLE OF PERCENTAGES OF COMPONENT COLORS IN THE CONNECTING HUES OF THE
CHROMATIC SCALE.
The following table shows the relative percentages, in color-wheel
measurement, of the two components in each of the hues connecting
adjacent pairs of the six spectrum colors as represented on the
original Plates of this work; together with an equal number of exact
intermediates (not shown on the Plates), the latter in lower-case type
and not indicated by symbols.
Number. Color. Red. Orange. Yellow. Green. Blue. Violet. Wavelength.[27]
1 Red 100 644
2 90 10
3 O-R 80 20
4 70 30
5 OO-R 60 40
6 50 50
7 R-O 40 60
8 30 70
9 OR-O 20 80
10 10 90
11 Orange 100 598
12 96 4
13 OY-O 91 9
14 86 14
15 Y-O 80 20
16 73.5 26.5
17 O-Y 65 35
18 56.5 43.5
19 YO-Y 47 53
20 36.5 63.5
21 O-YY 25 75
22 13.5 86.5
23 Yellow 100 577
24 87 13
25 YG-Y 75 25
26 64 36
27 G-Y 55 45
28 46 54
29 GG-Y 39 61
30 31 69
31 Y-G 24 76
32 17 83
33 GY-G 11 89
34 6 94
35 Green 100 520
36 96.5 3.5
37 GB-G 93 7
38 90 10
39 B-G 85 15
40 81 19
41 BB-G 75 25
42 69 31
43 G-B 61 39
44 54 46
45 BG-B 45 55
46 36 64
47 G-BB 25 75
48 13 87
49 Blue 100 473
50 84 16
51 BV-B 72 28
52 64 36
53 V-B 54 46
54 47 53
55 B-V 40 60
56 32 68
57 VB-V 22 78
58 12 88
59 Violet 100 410
60 3 97
61 VR-V 7 93
62 11 89
63 R-V 18 82
64 24 76
65 RR-V 33 67
66 41 59
67 V-R 52 48
68 64 36
69 RV-R 74 26
70 83 17
71 V-RR 90 10
72 95.5 4.5
TABLE SHOWING PERCENTAGE OF WHITE AND BLACK, RESPECTIVELY, IN EACH TONE
OF THE TONE OR LUMINOSITY SCALES.
All of the vertical scales in the original Plates of this work (the
scale of carbon grays alone excepted) contain the following percentages
by color-wheel measurement:
TONE. PERCENTAGES.
White. Color. Black.
(White) 100
(g) 70 30
f 45 55
(e) 32 68
d 22.5 77.5
(c) 15 85
b 9.5 90.5
(a) 5 95
(Full Color) 100
(h) 64 26
i 55 45
(j) 41 59
k 29.5 70.5
(l) 20 80
m 12.5 87.5
(n) 6 94
(Black) 100
One of the most serious difficulties encountered in the preparation
of the Plates of this work was the apparent impracticability of
reproducing satisfactory shades of pure colors. This originated in the
fact that there seems to be no substance (pigment, dye, or fabric)
which represents a true black, all reflecting more or less of white
light, and consequently producing shades which are dull or broken.
The difficulty is increased by the additional fact that any black
pigment mixed with almost any color falls short of even the color-wheel
mixture in purity of hue in the resulting shades, owing to the very
considerable amount of gray in all black pigments. Chromolithography
can be made to produce clearer and better shades of the pure colors,
but is distinctly objectionable for the purpose of a work of this
kind owing to eventual oxidation of the oil or varnish with which the
pigments are combined in lithographic inks, causing a change of hue;
reds becoming more orange, blues more greenish, etc., in course of time.
While the absence (in large part) of pure chromatic shades is much
to be regretted, the defect is not so serious, _from the standpoint
of utility_, as might appear at first sight; for while saturated or
darkened pure colors are not uncommon in the animal, vegetable, and
mineral kingdoms, more or less broken dark colors are infinitely more
so; and since the latter are greatly increased in number by the defect
mentioned the actual result is rather an advantage than otherwise.
It will doubtless be noticed that there is a conspicuous difference
in relative darkness between shades of yellow and contiguous hues on
the one hand and corresponding ones of violet and adjacent hues on the
other, as if the percentage of black in each were very different. This,
however, is entirely the result of difference of luminosity of the
two sets of colors, that of yellow being between 7000 and 8000 while
that of violet is only about 13;[28] for the percentage of black in
corresponding tones of the vertical scales is precisely the same for
each color throughout the chromatic scale of this work.