If a painting uses only red, yellow, and blue, what type of colour scheme is it?

Correct answer: Primary colour scheme

A primary colour scheme is built mainly from the traditional primary pigment colours: red, yellow, and blue. Since the painting uses exactly these three basic hues, it is classified as a primary colour scheme. A complementary scheme uses opposite colours, a monochromatic scheme uses one hue with variations, and a neutral scheme relies on colours such as grey, white, or black. Thus, option A is correct.