In these parts, wasps and other flying critters that aren't your friends, are particularly attracted to the color black with aggressive behavior. I have witness it directly myself on a cycling trip when stopping in at a covered bench thing, my friend being swarmed upon immediately after removing his cap and exposing his black hair. Stung on the scalp like a dozen times, he had to ride off in an ambulance.
I see they are marketing men's suits now with a heat reflective fabric that doesn't allow the temperature to penetrate, something new that a guy at a university developed. I haven't seen it in regular work clothes. The world favors white collar.