Prismology

Sir Isaac Newton is often credited with discovering the color spectrum by using a prism to break apart light. On this webpage, we use the very same technique to analyse the elements of the colors that we see. The following is a series of revealing images that are "prismized" which allows us to arrive at some enlightening conclusions.   

Before beginning this section, you should know that the two primary systems of color are called: Additive and Subtractive. The Additive system is used when projected light is involved. When colored lights overlap, various colors are seen by the eye. Subtractive color involves the absorption of light. In this case, the eye sees the reflection of light. For example, the feathers of a yellow canary will absorb blue-violet rays of the sun and reflect red and green light. This appears yellow to our eyes.

In the images below, we are able to switch between color mixing systems by using offsetting backgrounds. (However, computer monitors always use additive color because of the projection of light.) Our goal is to determine the primary colors of each systems and see how they react under a prism. The interesting thing is that by placing a 'selected' color on a white background, you can see the 'subtractive' colors which make up the color. By placing the color on a black background, you can see the 'additive' colors. As you shall see, the prism can also be used to quantitatively identify the 'best' primaries.

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Other Articles:
Color Poster
Color Basics
Color Mixing
Color Models
The Color of Music
Prismology
Color Math
Color Glossary
Color Theory
Color Techniques

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Using a prism, you can see the three primaries. With a black line on a white background, you can see true Cyan, Magenta, and Yellow. With a white line on a black background, you can see the true primaries Red, Green, and Blue (Blue-violet).

Note that as the line sizes changes, the number of colors you see increases. The reason for this is because as the lines of color begin to converge, we are able to perceive more colors.

For each of the recognizable colors below, you can use the prism to determine the 'primary' colors used to make them. Note that the primaries are subtractive when viewed on a white background, and additive when viewed on a black background.

After "prismizing" the colored circles below, we see that the spectral colors are visible in various proportions. Notice the changes in primaries as we move around the circle and how the primary values change in the interior of the circle as each color gets lighter. (Please note that the illustration is just an approximation of what we actually see. Only by using a prism on a diagram such as this can you get a true sense of the proportional primaries.)