What yellow and purple do, some say

CLASH

Think of how certain colors or patterns might visually compete when placed side by side, like a fashion no-no. This word also describes a loud disagreement.

This clue plays on the idea that yellow and purple are colors often considered to clash when paired together. The word "clash" also fits because it’s a common term for colors that don’t complement each other well. The phrase "some say" hints that this is a subjective opinion, reinforcing the answer as a verb meaning to conflict or contrast sharply.