The utmost beauty of colouring depends on the great principle of varying
by all the means of varying, and on the proper and artful union of that
variety.
I am apt to believe that the not knowing nature's artful and intricate
method of uniting colours for the production of the variegated
composition, or prime tint of flesh, hath made colouring, in the art of
painting, a kind of mystery in all ages; insomuch, that it may fairly be
said, out of the many thousands who have labour'd to attain it, not
above ten or twelve painters have happily succeeded therein; Correggio
(who lived in a country village, and had nothing but the life to study
after) is said almost to have stood alone for this particular
excellence. Guido, who made beauty his chief aim, was always at a loss
about it. Poussin scarce ever obtained a glimpse of it, as is manifest
by his many different attempts: indeed France hath not produced one
remarkable good colourist.
Rubens boldly, and in a masterly manner, kept his bloom tints bright,
separate, and distinct, but sometimes too much so for easel or cabinet
pictures; however, his manner was admirably well calculated for great
works, to be seen at a considerable distance, such as his celebrated
ceiling at Whitehall Chapel: which upon a nearer view will illustrate
what I have advanc'd with regard to the separate brightness of the
tints; and shew, what indeed is known to every painter, that had the
colours there seen so bright and separate been all smooth'd and
absolutely blended together, they would have produced a dirty grey
instead of flesh-colour. The difficulty then lies in bringing _blue_,
the third original colour, into flesh, on account of the vast variety
introduced thereby; and this omitted, all the difficulty ceases; and a
common sign-painter that lays his colours smooth, instantly becomes, in
point of colouring, a Rubens, a Titian, or a Correggio.
_Hogarth._