Sometimes the device of intruding a strong touch of the complementary color will have the appearance of raising the color to a higher key. for instance, if the greens are to gray, and are somewhat dull and uninteresting in color, the close proximity of a brilliant bit of red will restore it, and it will assume a more vivid tone of green at once.
With oil and water colors, it is usual to mix two or more together to produce greens and violets ; but it is not advisable to do this with mineral colors.
One of the elementary principles of art, or rather of color, is that the combinations of the two primary colors, blue and yellow, makes the secondary green, and that blue and red will produce violet shades ' but with mineral colors, it is well to confine this fact to theory, and to purchase greens and violets ready made. These may be modified by other colors, -- the greens with yellow, blue, or brown ; the violets with blue or carmine, to any desirable shade ; but it is impossible to obtain a gamut of pleasant tones of green by mixing blue and yellow. In reality, they injure or neutralize each other.
The reason is obvious, -- the greens of the mineral palette are mad from metals and materials that produce green in infinitely better,
