It's immaterial that the original Border Tradition was racist or not; the fact that it probably was is neither here nor there to the current revival of he practise. Agricultural labourers living in cultural isolation in the 18th / 19th even early 20th centuries were operating under who-knows-what kind of conscience or criteria. Pagan*? Racist? Who cares?

For sure this is interesting culturally, historically and in terms of genuine folklore, but the current practise is about as far from all that as you can hope to get, hence, presumably, the wishful thinking that the 1970s Folk Zeitgeist that persists in the daly 21st Century is a bona-fide Tradition, rather than a bogus fabrication by people operating at some considerable cultural & historical remove from the old lore & its practitioners.

* Looking at the names some of these latter day revival niggering sides with all their Imbolcs and Beltaines (see Noreen's link below) it seems obvious just how secure their grasp of folklore is. This is LARPing Steamfolk pure and simple; fakelore at it's very finest. Whatever their reason is for blacking up, to so in the context of the multi-cultural UK of 2014 is insensitive at best, and all the more for the excuses we've seen trotted out here.