The combination of red, blue, and green light produces which color?

• A. Yellow light
• B. Blue light
• C. White light
• D. Black light

Answer: (C)

Additive color mixing: when red, green, and blue light are combined at full intensity, they produce white light. Our eyes detect those three colors with separate cone types, and stimulating all three at once is perceived as white. If you mix only two of them, you get other colors—red and green make yellow, red and blue make magenta, green and blue make cyan. Blue light alone stays blue, and black light isn’t produced by mixing visible lights at full intensity (it refers to UV or to the absence of light). So the combination of red, blue, and green light yields white.