I see your point.
There are 2 kind of fixes for the 'dark theme support':
The first is to make all UGENE icons, buttons and other standard UI controls to look correctly (be visible) with the default system dark theme provided by an OS. This can be considered as a high priority issue for us and will be fixed ASAP.
The second is a compete dark theme support for internal UGENE UI: every area drawn by UGENE with no use of system UI primitives at all. This task is much bigger than the first one.
I created a JIRA issue for it (
https://ugene.dev/tracker/browse/UGENE-7610), but can't confirm the completion time of this feature due to limited resources in the team. The only way I see to guarantee the fix to be included into the next release is the ordering it as a part of "commercial support" - such issues are fixed first.