That looks AMAZING!! Just my personal taste would be to darken slightly to #262626
to provide clearer contrast between the background and text. But, understand, were are just talking about minor nits now, so everybody will have their own preference.
Just as an experiment, you might do 2 or 3 screen shots with variations and open a poll for the eGroupware community and customers to vote on?
That’s a good way to spur some community involvement and make everybody feel like they have been a part of eGroupware and have a bit of pride in their favorite groupware package because they helped.
No matter what you do, that dark mode is more than 100% acceptable and much easier on the eyes than the light versions.
Keep up the great work!