Apple Watch screen bright, watch is very hot when charging

My Series 4 Apple Watch randomly went super bright (green, yellow, blush color) this morning after a run. It has standard wear and tear. I did not drop it or anything before this happened - just rinsed it off after my run (which I do every time after runs). It seems to be working, as it will buzz when receiving phone calls or messages, but it's basically useless, as I cannot see anything (see images). It changes random patterns when pressing the digital crown. I can even turn it off by holding down the side button and swiping in the proper location to turn off. Restarting did not fix the issue. It properly tracked my movements, etc. during the day until it died (presumably because the screen killed the battery). So the watch actually seems to be functioning. If I place it on the charger, though, it heats up very quickly. Anyone have an idea what's happened? Thanks!