Social media advice says you shouldn’t wear black in your profile photo. It says you should stand in front of a neutral background color. That’s great advice for people who don’t wear black and prefer neutral colors, but it also makes some assumptions that may be lacking in reality and preference.
It seems the advice assumes dark hair is present, which I suppose could be problematic against a dark background. In that case, combined with a black shirt, one’s social media face at 50 pixels square could become something of a small disheveled puzzle piece. Or the imaginary space around a prune.
If your skin is of a beautifully dark hue, wearing black and being against a black background may be problematic if the lighting is poorly done. Then again, it may be quite interesting if the lighting is excellent.
Following on from that, it seems that if you have blond or red hair, you should not wear bright clothes or be against a bright background, although white should be fine.
On the other hand, if you have grey hair, you probably should avoid white or neutral backgrounds and grey shirts. In fact, if you have grey hair (or no hair), you might be wise to wear a black shirt and use a dark background.
The idea is to not get lost. It’s to stand out. Of course, if you prefer to not stand out, that’s okay too. Be a rule breaker.