Hi Timo, On Wednesday, March 8th, 2023 at 15:12, Timo Wilken wrote: > > QUESTIONS > > > > Do you know of any defaults in Icecat or Chromium that might be preventing the expected functionality from working correctly? As far as I understand the versions of both Icecat and Chromium in Guix are supposed to support all the features required for automatic color scheme activation to work. > > It works for me if I disable IceCat's "resist fingerprinting" option (search for "fingerprint" on about:preferences). I assume that sites can fingerprint your browser based on its theme (light or dark), which is presumably why this option disables the CSS feature. Aha, indeed. The option is also available from the Application menu → IceCat Settings → Privacy and Security. Thanks for checking, Timo, I'll check for similar settings in Chromium. Cheers,