* Fix #39417

* Use pseudo elements instead of mask-image so that labels retain subpixel AA

* Use ellipsis and disable fade for HC theme, and support hover colours

* Make requested changes and start on fixing transparency issue

* Merge all colours underneath tabs to fix transparency issue

* Rename color function, move workbench background into themes

* do not allow to change workbench background

* 💄

* fix npes and clean up

* fix class names

* remove blank line

fixes #42158