What is the most precise identification of a tertiary colour on a traditional twelve-part colour wheel?

Correct answer: A mixture of a primary colour and its neighbouring secondary colour

On a traditional twelve-part colour wheel, a tertiary colour occupies the interval between a primary and the neighbouring secondary colour made from that primary and the next primary. Examples include yellow-orange and blue-green. A mixture of two primary colours produces a secondary colour, while complementary mixtures tend toward neutral tones; black and white produce value changes, not tertiary hues. Therefore, option A is precise.