A painter wants to reduce the intensity of bright orange slightly without making it muddy. What is the best method?

Correct answer: Add a very small amount of blue

The governing concept is complementary colour neutralisation. Blue is complementary to orange, so a very small amount of blue can lower orange’s saturation or intensity. The amount must be added gradually because too much blue will make the mixture dull, greyish, or muddy. More red or yellow changes the hue toward another orange, while black mainly darkens the colour rather than carefully reducing its intensity.