Where Does Color Come From?
Click to explore color and prisms.
Why do we see colors? Light from the sun or from a lamp seems to have no particular color of its own. It appears simply to be "white" light. However, if you pass the light through a prism, you can see that it actually contains all colors, the same effect that occurs when water droplets in the atmosphere separate light into a rainbow. A colorful object such as a leaf appears green because when white light strikes it, the leaf reflects only the green wavelengths of light and absorbs the others. A white object such as a white flower appears white because it reflects most of the wavelengths that strike it, absorbing relatively few. Inks, dyes, or pigments in color prints also selectively absorb and reflect certain wavelengths of light and so produce the effect of color.
Although light from the sun appears colorless or "white" it actually contains a range of colors similar to a rainbow. You can see these colors using a prism to separate them out.
White objects reflect most of the wavelengths of light that strike them. When all of these wavelengths are combined, we see
white. On the other hand, when all of them are absorbed, and none reflected, we see black.
A green object such as a leaf reflects only those wavelengths that create the visual effect of green. Other colors in the light are absorbed by the leaf.