Additive Colors — Red, Green & Blue
Additive color systems, such as televisions or computer monitors, start with no light (black). Additive colors are produced by light sources and the wavelengths create color. Red, green, and blue are called additive colors because when two of them are added (mixed), one of the subtractive colors is produced. Combining all three additive colors with equal intensities produces white. Combining all three additive colors with different luminosities reveals the full gamut of colors.
Red + Green + Blue = White
Blue + Green = Cyan
Blue + Red = Magenta
Green + Red = Yellow
Subtractive Colors — Cyan, Magenta & Yellow
Subtractive color systems, such as paint or ink, start with white light. Subtractive colors are produced by light reflecting off of opaque surfaces. Some of the light that strikes the surfaces is being absorbed, or subtracted, by the surfaces and the rest of the light is reflected. The variation in mixtures of wavelengths being absorbed and reflected creates colors. Combining all three subtractive colors with equal intensities produces black, because all colors are subtracted.
Cyan + Magenta + Yellow = Black
Subtract Red, reflect the Green & Blue = Cyan
Subtract Green, reflect the Red & Blue = Magenta
Subtract Blue, reflect the Red & Green = Yellow
Two subtractive colors together produce an additive color because each of the two subtractive colors absorbs (subtracts) additive colors.
Magenta + Yellow subtracts the Green & Blue is seen as Red
Cyan + Yellow subtracts the Red & Blue is seen as Green
Cyan + Magenta subtracts the Red & Green is seen as Blue
Now you’re a little smarter, Girlfriend — And so am I.