Case 1: Blue guy hates green people. Red and yellow are fine, but green people are sub-human and don’t deserve the same treatment as blue, red, and yellow. According to this comic, you just give them gray people to refocus their racism and then blue and red will both hate gray together.
Case 2: Blue guy thinks only blue people are true human. If you’re not blue you don’t deserve to be treated the same as blue. Giving them gray people to be racist against will not change anything, it’s just one more color that’s not blue.
I’m saying case 2 is what racism looks like in real life in 99% of cases. But even in case 1, I doubt the blue racist would suddenly be ok with red people just because gray are worse.