Unless there was a genuine racist reason for them originally painting their faces black, then I don’t see why they can’t carry on with their tradition. Anyone who is offended by some non racist face painting needs to get out more and find something to be properly worried about.
If the roots are in some way “racist”, then I’d agree that some traditions need to be brought more up to date.
It’s the difference between blacking up to look like a chimney sweep and blacking up to be a black and white minstrel – one is harmless, one is offensive.
Now we can all just quote different internet links to each other to argue which it is!