brightness inventory bug

So while checking the new enchanting thing, I discovered that when you put a stack [64] (did not check for other amounts) Lapis lazuly by shift in the enchanting table the inventory list turns darker and if you quit the proces it stays that way, but if you shift it back from the workbench it's all bright again. I'm not sure if it is supposed to do that, but you can check it out. I'm on /gamemode 2