Here is the version I intend to put in the repo unless someone finds something wrong - omv-extras.org/testing/openmediavault-docker-gui_4.1_all.deb
I tried clearing the browser cache and also tried using a browser that has never visited OMV. Neither improved the contrast. Same problem with the previously posted edits to some files that were supposed to fix it. I tried again after upgrading to openmediavault-docker-gui_4.1_all.deb, no change.
OMV 4.x - ASRock Rack C2550D4I - 16GB ECC - Silverstone DS380