I vote black.
How has he been dying his hair for so long? Why haven't we met his hairdresser or product supplier? Why haven't any of the ladies or gents asked who does the magic? Does the wuxia setting just magically color people's hair for dramatic effect? If so, when is his cultivation going to cause a new magical makeover? And when are we going to see another bubba with red and white hair? If he's unique, why don't people talk about it?
The problem with magic like this, is it raises so many questions. When the author doesn't supply any answers, it breaks immersion, like MC holding a Starbucks. I guess, "Simon's a lone, red panda hero, 'cause they're cool." Why not give him some Air Jordan's or a Super Mario tattoo while you're at it?
If his mom got a stylist backstory, I'd change my vote, but then he'd need to carry product wherever he went to keep the look fresh
![Smile :) :)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
Black ends that distraction.