wilarsenyMy black belt also has similar white stripes/spots, although not as extensive as yours. I had applied some leather conditioner to buff them out. According to the vendor's comment on the 1st discussion page, he calls them 'bloom', and it is wax coming out of leather. I thought it was due to leather dryness at first.
wilarsenyYep, like @zz_upenn said, that looks like bloom. Don't fret! From my previous comment:
Some of you may notice that there is a bit of a white-ish film on the belts in the photos; this is no accident, as it is the tallow and wax from the finishing process. It will quickly disappear with use, or can be buffed off to achieve a nice shine. It's also indicator that this leather is the real deal English bridle leather and not the American version of the stuff.