In the first release of 1.9, and 1.9.2, if you do the /give command to get a player head, /give @p minecraft:skull 1 3

, it will flash your inventory with black in your left hand slot, and if you put the head on, it will flash black all your armor slots.

I don't know what's happening, but it's kind of getting annoying with the black flashes. (My Minecraft username is OwenGLG, just so you know.)