Primary Subtractive Colors

The complementary colors (cyan, yellow, and magenta) are also commonly referred to as the primary subtractive colors because each can be formed by subtracting one of the primary additives (red, green, and blue) from white light. This tutorial explores how the three primary subtractive colors interact with each other, both in pairs or all together.

The tutorial initializes with magenta, cyan, and yellow filled circles randomly bouncing within the confines of the tutorial window. As the circles cross each other, the corresponding complementary color (red, green, or blue) is displayed in the intersected area. When all three circles intersect, a total lack of color (or black) is produced. In order to control the movement of the circles, click on the red manual button, which toggles the tutorial between automatic and manual modes. In manual mode, the mouse cursor can be utilized to click and drag the circles anywhere within the confines of the tutorial window. In addition, a blue Auto button appears, which will return the tutorial to automatic mode.

Yellow light is observed when all blue light is removed from white light, magenta forms when green is removed, and cyan is produced when red is removed. The color observed by subtracting a primary color from white light results because the brain adds together the colors that are left to produce the respective complementary or subtractive color. When any two of the primary subtractive colors are added, they produce a primary additive color. As an example, adding magenta and cyan together produces the color blue, while adding yellow and magenta together produces red. In a similar manner, adding yellow and cyan produces green. When all three primary subtractive colors are added, the three primary additive colors are removed from white light, leaving black (the absence of any color). White cannot be produced by any combination of the primary subtractive colors, which is the main reason that no mixture of colored paints or inks can be used to print white.

Contributing Authors

Matthew Parry-Hill and Michael W. Davidson - National High Magnetic Field Laboratory, 1800 East Paul Dirac Dr., The Florida State University, Tallahassee, Florida, 32310.