Why don't more black people put crazy colors in their hair?

Dying your hair colors other than natural colors is just one simple fad that is rapid in some races more so than others. Certain trends are expressed differently by different races. Maybe the blacks you meet only see White people who dye their hair different colors. It's the same as being gothic or emo, blacks aren't use to seeing black emos or goths. Or if you want to turn it around, White people aren't use to seeing white people wear do rags, or big chains around their necks, or wearing urban styles.