What colour is obtained when more red is added to violet made from red and blue?

Correct answer: Red-violet

Violet is produced by mixing red and blue. If more red is added, the balance of the mixture shifts toward red while it still retains some blue, so the resulting hue is red-violet. Blue-green requires blue and green, yellow-orange requires yellow and orange, and light green is unrelated to this red-blue mixture. Thus option C is correct.