How Colors Mix in Light versus Pigment

Imagine if light was available in paint pots or art tubes. Red light was inside one, yellow light inside the second and blue light inside the third. How would the colors mix? Bizarre as it may sound, they would mix in opposing ways to art pigments.

The Visible Spectrum of Light

Behavior of Light Waves

Bright white light comprises all the colors, as can be seen if a beam of light was shone through a prism. Red light has the longest wave length of the visible spectrum and can be perceived on an outer edge of the split light beam. Violet light has the shortest wave length of the visible spectrum and would be visible on an opposing edge. All the other colors we see will lie somewhere between, in the order of: violet, blue, green, yellow, orange, red and magenta. All these colors are but a hair-thin slice of the electromagnetic radiation. The Primary Colors of Light

Now let’s look at the behavior of colored light versus pigment. Firstly, the primary colors of pigment are magenta (not red, as red is a secondary color), yellow and cyan, as can be seen in printing ink. With these three colors, any color can be mixed. Mix all three together and black will result.

But the primary colors of light are the secondary colors of pigment, which are red, green and violet. In other words, the secondary colors of pigment are the primary colors of light.

Mixing Colored Light

Take a pot of red light and a pot of green light; two primary colors of light, and let them overlap, and yellow will shine back. Take a pot of violet light and a pot of green light, again, two primary colors of light, and bright cyan will result. Mix all three primary colors together, and you will not get black, as would be the case of pigments, but white.

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Introducing more pigments into a paint mix will sully its appearance, and browns, greys and (ultimately) black will result. But doing the same with light will merely create a paler light, and (ultimately) white. Stare at a colored light, and its complementary color will imprint upon the retina. This will be seen when the eyes are closed. A red light will leave a green afterimage; a yellow light will leave a violet afterimage. It can be seen from this, that light and pigments have something in common: they have the same complementary colors.

Complementary Colors of Light and Pigments

Complementary colors are two opposing colors that can be found on the color wheel. We can see in both the ‘light wheel’ and the ‘pigment wheel,’ that the complementary color of green is magenta; the complementary color of violet is yellow, and the complementary color of blue is red. In both examples of light and pigments, placing complementary colors side by side will create a shimmering effect, often used in art. However, mix any two complimentary colors together, and in light, white will result; in pigment, black will result. Pigments versus Light in Color and Art

When it comes to color behavior, light behaves in opposing ways to pigments. The primary colors of light are the secondary colors of pigments. Mixing a given color pair together will bring different results in light and pigment. Adding more colors to the mix will sully or darken the color in paint, but will appear paler and brighter in light. The only thing they have in common is their complementary colors. But mixing complementary colors together will result in black in pigment; but white for light.