An artist wants to slightly mute a very bright red while keeping its value nearly unchanged. What should be added?

Correct answer: A very small amount of green

The governing concept is the difference between saturation and value. Green is complementary to red, so a very small amount can reduce red’s chromatic intensity and mute its brightness while keeping its value relatively close. The addition must be tiny because excess green will make a dull brown or neutral mixture. A large amount of black lowers value, white raises value and may reduce transparency, and more red increases intensity. Therefore, option B is correct.