What are the three additive primary colors of light, and how do they combine?

• A. Red, Green, and Blue are the additive primaries; when combined at full intensity, they produce white light.
• B. Yellow, Magenta, Cyan produce white.
• C. Red, Green, and Yellow produce white.
• D. Red, Blue, and Yellow produce white.

Answer: (A)

In light, colors are created by adding wavelengths, so the primary colors are red, green, and blue. When all three are emitted at full intensity, they combine to produce white light, because together they span the full range of visible wavelengths.

The other options mix colors that aren’t the additive primaries. Yellow, magenta, and cyan come from subtractive color systems (like inks and printing) and don’t produce white when combined with light; in fact, they’re used to subtract color rather than add it. Also, red, green, and yellow aren’t a true additive primary trio, since yellow already represents red plus green in light.