If a painting uses only orange, green, and violet, which scheme is it based on?

Correct answer: Secondary colour scheme

Orange, green, and violet are the three commonly taught secondary colours: orange comes from red plus yellow, green from yellow plus blue, and violet from blue plus red. Since the painting uses only colours from this category, it follows a secondary-colour scheme, so option B is correct. A primary scheme uses red, yellow, and blue; monochromatic uses one hue with variations; black-and-white uses no coloured hues.