A picture in black and white seldom makes its appearance; some works of Polidoro are examples of this kind of art. Such works, inasmuch as they can attain form and keeping, are estimable, but they have little attraction for the eye, since their very existence supposes a violent abstraction.
863.
If the artist abandons himself to his feeling, colour presently announces itself. Black no sooner inclines to blue than the eye demands yellow, which the artist instinctively modifies, and introduces partly pure in the light, partly reddened and subdued as brown, in the reflexes, thus enlivening the whole.—Note GG.
864.
All kinds of camayeu, or colour on similar colour, end in the introduction either of a complemental contrast, or some variety of hue. Thus, Polidoro in his black and white frescoes sometimes introduced a