REFRACTION
liant and dramatic demonstration. But in greater or less degree, the law is always at work. Any painter who has posed his sitter against a red background, for instance, must have noted how the red ground brought out the green tones in the flesh. And has it ever occurred to you why never a portrait was painted against a bright blue background. Simply because there has never been found a human being modest enough to stand for the jaundiced presentment of himself that would be the natural result—yellow being the complementary of blue.
It results from this that no color has any definite and fixed existence of its own—once it is out of the tube. It is changed and varied infinitely as its surroundings change and vary. Even when it is fixed definitely under the varnish of some masterpiece, it remains subject
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