Any substance or object which reflects none of the rays which fall
upon it, but absorbs all, appears black; no rays reach the eye, and
there is an absence of any color sensation. Coal and tar and soot are
good illustrations of objects which absorb all the light which falls
upon them.
131. How and Why Colors Change. _Matching Colors._ Most women prefer
to shop in the morning and early afternoon when the sunlight
illuminates shops and factories, and when gas and electricity do not
throw their spell over colors. Practically all people know that
ribbons and ties, trimmings and dresses, frequently look different at
night from what they do in the daytime. It is not safe to match colors
by artificial light; cloth which looks red by night may be almost
purple by day. Indeed, the color of an object depends upon the color
of the light which falls upon it. Strange sights are seen on the
Fourth of July when variously colored fireworks are blazing. The child
with a white blouse appears first red, then blue, then green,
according as his powders burn red, blue, or green. The face of the
child changes from its normal healthy hue to a brilliant red and then
to ghastly shades.
|