Adwaita: Switches in dark mode are hard to see (low contrast)
Awesome work on the Adwaita refresh! I love it. Huge congrats to all!
There's one small thing that is a little irritating, and that's the contrast of the switches while in dark mode. They used to have the text "ON" and "OFF" (or "1" / "0"), which made them a little more identifiable in the old version of the theme. However, now that they've been reworked (#1372 (closed)) — and look nicer and more modern with the roundness and the lack of interior labels — the off mode is particularly hard to spot.
I've taken screenshots of Builder in light and dark modes to illustrate:
Light mode
It's pretty good and obvious.
Dark mode
Dark mode's off switch gets almost completely lost in the background. The on mode also has some problems with the knobby part of the switch, but the selected on mode helps, at least.
Suggestions
I'd suggest lightening the circular knob part, so even the on switch has a little bit of contrast... and darken the off background part, perhaps.
Here's a very quick mockup I made in The GIMP:
And here's an alternate with both knobs brightened up a little bit more... with the ON mode even a touch brighter than off mode: