So I started a world on survival and it started raining. Then I saw constant lightning flashes and then my house turned completely white. I live in a jungle biome, and when i exited my house the trees were all solid green blocks, even the vines. The grass blocks were all green and the dirt was white. The I entered the nether and it seemed ok. About two days later, i was in creative making a base for villagers to live when suddenly, blocks flashed purple and then flashed again with a white outline. When it flashed, redstone lamps looked like floating glowstone dust.
Then, after all the flashing, my villager spawn egg was a flat brownish block and the items in my inventory said "no texture".
Then there was different blocks and textures all over the screen. I tried to take a screen shot, but it showed up as the picture I'd taken before. I was worried and paused the game, and the words were in huge white print in a different font. I dont have mods or texture packs, so I dont know why this happened. It seems to happen when something big happens, like when I spawn a lot of villagers or during a lightning storm