Thanks for the kind words!
Carol Huang and I definitely considered theme support whilst designing this so that all still works.
WRT the brightness of the UI, we really tried to strike a balance between the Photon colour palette and how the colours come through on Mobile. For example, we actually created a “mobile-specific” colour palette on Mobile that uses slightly more muted colours (the ones you’re seeing).
But its hard because of fragmentation on mobile and the devices also have brightness so readily adjustable. We’ve heard similar feedback elsewhere too and clearly, we still have some work to do. :)