Turn off High Contrast for Allpub

Press CTRL+ALT+DEL and you will see a lock screen with just a cancel button and two icons in the lower right corner:  Network and Ease of Access

Click the Ease of Access icon and disable any settings that have been enabled, like High Contrast or Narrator.

Click cancel and the system should return to "normal" after a few seconds.  If not, trigger a restart using PCM.

See the attached picture for reference.