Review Board 7.1 will ship with Dark Mode enabled all throughout the

product. We introduced it as a beta, opt-in feature in 7.0, but we

didn't have it universally, as we didn't have time to convert the Admin

UI or some of the components in Djblets. Since then, we've made progress

on pretty much every component the Admin UI depends on.
We now support Dark Mode all throughout. This includes all the Admin

settings pages, dashboard widgets, security checks, and more. Colors

were converted to Ink color palettes, buttons to Ink buttons, and

various styles fixed.
An upcoming change will enable Dark Mode for all users based on system

settings.
As a note, the support banner in the Admin Dashboard is bright, but there

are plans to make further changes specifically to this area in an

upcoming change, so it will remain as alert styling for now.

Tested all pages in the Admin UI in dark mode and in light mode, checking

for any visual issues.
Screenshots on the review request are included just for notable pages.

Most use standard dark mode styling and color palettes and aren't notable.