Never heard of the OPs contention.
Here, it’s the other way round - in so far as national dress for men is predominantly white and even more so black for women.
But - occasionally for some godforsaken reason they have these lavatory signs in negative. So they are, for example, a woman in headdress and a man in headdress - but the man is black and the woman in white. I cannot tell you how many times I, other women, and men, accidentally stumble into the wrong bathroom because the signs are this way. (Bearing in mind two things in headdresses shape-wise are much closer than the stick-man with legs and stick-lady with skirt - so your brain tends to rely on colour).
The worst place for this is Dubai Airport Expo. Outside the media room everyone was constantly stumbling into the wrong bog.