Which colour is formed by mixing equal amounts of red and orange?

Correct answer: Red-orange

On the traditional colour wheel, red is a primary colour and orange is the adjacent secondary colour. Mixing equal amounts of these two neighbouring colours produces red-orange, a warm tertiary colour, so option C is correct. Yellow-orange requires yellow mixed with orange; red-violet requires red with violet; and blue-green requires blue with green. The equal quantity wording indicates a balanced version of the named tertiary mixture rather than one colour dominating the result.