While changing colour temperature the artist cooled every mixture by adding only blue. What problem may occur?

Correct answer: Mixtures may lose variety and become monotonous or muddy

The governing concept is colour temperature with variation in hue and proportion. Blue can cool a mixture, but using the same blue in every mixture may suppress the original hue differences and produce repetitive, dull, or muddy results. Option C is correct. Transparency is not automatically produced, paper colour does not change merely from mixing, and brush length is unrelated. Different cool colours and measured amounts provide richer temperature changes.