Which rule is most useful when naming a tertiary colour?

Correct answer: Write the dominant primary colour first

The governing naming rule is that the primary hue is written first when identifying a tertiary mixture, followed by the neighbouring secondary hue. Thus red-orange indicates a mixture leaning from red toward orange, and blue-green indicates blue toward green. Option A is correct because the order communicates the dominant hue bias. The other choices confuse naming with complementary relationships, value, or an absolute secondary-first rule.