Weird colors when mining and placing blocks

I was adding to my enchant room in minecraft when I started getting weird cut out blocks (same corner). I looked through and saw weird lines in purple and a sort of greenish color. I don't know if it was a visual glitch because it happened even when I re logged and fully shut the game, including the launcher (I didn't know if that would affect the game). It still does it now and to temporarily fix it, I have to mine and place the blocks in that same spot. It always comes back when I look at the corner from a different angle.