How many primary colors of light are used in additive color mixing?

• A. Two
• B. Three
• C. Four
• D. Five

Answer: (B)

Additive color mixing builds color by adding light. The primary colors of light are red, green, and blue. By adjusting how bright each is, you create different colors; more light from all three makes lighter colors, and all three at full strength give white. If you mix just two primaries, you get bright secondary colors like yellow (red+green), magenta (red+blue), or cyan (green+blue). Since three distinct primaries are used to span the color range, there are three primary colors of light. This is why screens use RGB subpixels to render images.