[FEATURE] Dark Mode

**Is your feature request related to a problem? Please describe.**
Please add a dark mode theme to all web interfaces. Even better, add options for (color) blind folks as well.

**Describe the solution you'd like**
Dark mode option - implement via CSS or whatever you like. A sun/moon toggle icon or similar on the landing page is helpful.

**Do you have a workaround?**
Well, I could use an extension to "darkify" it but that's often hit-or-miss.

**Comparable features in other tools?**
Most sites have one these days.

**Additional context**
My eyes and many others thank you in advance.