It would be a very interesting experiment banjoman! They do in fact 'white up' in Cote d'Ivoire for some traditional dances.

I think if woad or another colour were used, the Politically Correct Brigade would have the wind taken out of their sails. They'd probably feel a bit disappointed that there was no fight to be had.
I've often found in life that when someone gets on their soapbox looking for an argument, and one smiles, nods calmly and agrees with them, they look a bit downhearted!