.=--In studying the facts of color contrast and
color juxtaposition you will find that two pigments, if mixed in the
ordinary way, will have one effect; and the same pigments in the same
proportions, mixed not by stirring them into one mass, but by laying
separate spots or lines of the pigment side by side, produce quite
another. The gain in brilliancy by the latter mode of mixing is great,
because you have mixed the _color rays_, which are really light rays,
instead of mixing the _pigment_ as in the usual way. You have really
mixed the color by mixing _light_ as far as it is possible to do it
with pigment. You have taken advantage of all the light reflecting
power of the pigment on which the color effect depends. Each pigment,
being nearly pure, reflects the rays of color peculiar to it,
unaffected by the neutralizing effect of another color mixed with it;
while the neutralizing power of the other color being side by side
with it, the waves or vibrations of the color rays blend by
overlapping as they come side by side to the eye; and so the color,
made up of the two waves as they blend, is so much more vibrant and
full of life.

="Yellow and Purple."=--It is this principle which is the cause of the
peculiarity in the technique of certain "Impressionist" painters. The
"yellow lights and purple shadows" is only placing by the side of a
color that color which will be most effective in forcing its note.

Brilliancy is what these men are after, and they get it by the study
of the law of color contrast and color juxtaposition. The effect of
complementaries in color contrast is what you must study for this, for
the theory of it. For the practice of it, study carefully and
faithfully the actual colors in nature, and try to see what are the
real notes, what the really component colors, of any color contrast or
light contrast which you see. Purple shadows and yellow light
re-enforcing each other you will find to exist constantly in nature.
Refine your color perception, and you will be able to get the result
without the obviousness of the means which has brought down the
condemnation on it. Closer study of the relations is the way to find
the art of concealing art.

But yellow and purple are not the only complementaries. All through
the range of color, the secondaries and tertiaries as well as the
primaries, this principle of complement plays a part. There is no
color effect you can use in painting which does not have to do, m