rish. It is very important
that the painter should understand this characteristic of color. You
cannot be too familiar with the management of grays. If you try to
make your grays with negative colors, you will not produce harmonious
color, but negative color, and negative color is only a shirking of
the true problem. Grays made of mixtures of pure colors, balancings of
primaries and secondaries, that is, modifications of the tertiaries,
are quite as quiet in effect and quite as beautiful as any, but they
are also more luminous; they are _live_ color instead of _dead_ color.
Grays made by mixing black with everything are the reverse, and should
not be used except when you use black as a color (which it is in
_pigment_), giving a certain color quality to the gray that results
from it.

=Complementary Colors.=--Two colors are said to be complementary to
each other when they together contain the three primaries in equal
strength. Green, for instance, is the complementary of red, for it
contains yellow and blue; orange (yellow and red) is complementary to
blue; and purple (red and blue) is complementary to yellow.

The knowledge of complements of colors is very important to the
painter, for all the effects of color contrast and color harmony are
due to this. Complementary colors, in mass, side by side, contrast.
The greatest possible contrast is that of the complementaries.

Complementary colors mixed, or so placed that small portions of them
are side by side, as in hatching or stippling, give the tertiaries or
grays by the mixing of the rays.

=The Law of Color Contrast.=--"When two dissimilar colors are placed
in contiguity, they are always modified in such a manner as to
increase their dissimilarity."

=Warm and Cold Colors.=--Red and yellow are called warm colors, and
blue is called a cold color. This is not that the color is really cold
or warm, of course, but that they convey the impression of warmth and
coldness. It is mainly due to association probably, for those things
which are warm contain a large proportion of yellow or red, and those
which are cold contain more blue. There is a predominance of cold
color in winter and of the warm colors in summer.

From the primaries various degrees of warmth and coldness characterize
the secondaries and tertiaries, as they contain more or less
proportionately of the warm or cold primaries.

In contrasting colors these qualities have great effect.

=Color Juxtaposition