I got it running on the Pico 4 through SideQuest and the color passthrough feature itself works great, but haven't quite figured out the trick to getting a good key with the new passthrough algorithm yet.
EDIT: Just saw the other thread and realized I'm late to the algorithm discussion. Anyway, the Pico app works great despite the challenges I'm having with the new passthrough algorithm, and when I can get a good passthrough, the color makes it awesome. The Pico headset is much more comfortable than the Quest 2 IMO also.