I saw this with mutter 3.27.91 also. See https://ubuntuforums.org/showthread.php?t=2386454 which was reported before 3.27.92 was available.
** Also affects: xorg (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xorg in Ubuntu. https://bugs.launchpad.net/bugs/1753752 Title: Blueish screen pixels after gnome on xorg login To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/mutter/+bug/1753752/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp