Which is the complement of the primary colour red on the traditional colour wheel?

Correct answer: Green

The governing concept is complementary colour pairing. On the traditional red-yellow-blue colour wheel, green is produced by combining yellow and blue, the two primaries that do not make red. Green lies opposite red, so option B is correct. Orange is opposite blue, and violet is opposite yellow; yellow itself is another primary colour and is not red’s complementary partner.