The UI color glitches out, and the color saturation shoots up, with an unknown pattern.

Button and interactable elements like links remain intact on hover or select, but other text get overlayed on hover. Sometimes, it recovers after a highlight on the text element. 

prtscn also unexpectedly alters color before the screen capture, so the screenshot is not 100% accurate.

This can be reproduced by installing the MC launcher from curseforge and launching it from there. 

The graphics renderer itself is likely broken, as the MS login page bg image also contains unnaturally high saturation and brightness.