I feel incredibly dumb, but here is what I did:
everything that is purple was yellow before.
I pressed some button on my keyboard accidentally and this happened
This is how it was
Try pressing 'F9' to change back to the legacy canvas. It looks like you pressed 'F11' and switched to the OpenGL canvas.
I cannot thank you enough.
This might be a good read if you don't know what the canvases are: