I was confirmed as allergic to PPD (along with a couple of other things) a few years back, via patch testing from a dermatologist.
I don't remember black clothing being mentioned at the time, although I was definitely warned off hair dye.
I'm currently wondering whether an old (much beloved!) leather jacket of mine is causing a reaction on the sides of my neck, where it would be touched by the collar. I wear it infrequently enough that it's the only thing I can thing of that night have triggered it, given that I'm very careful with washing powder/cosmetics/exposure to other allergens. Does anyone have any experience with this, I guess PPD-allergic people who've found that it isn't just hair dye that sets them off?!