Below is an example that is still using gray tiles.
- I tweaked the algorithm to get the predominant colors a little and
- added a logo outline (which is actually a shadow 1% bigger then the logo itself) that helps distinguish the logo from the background (e.g. see Firefox, Chromium and Chrome)
Note: The tile is using the second predominant color (modulated with +30% in Hue), while the shadow uses the first
When I tried with white tile, the imagemagick didn’t colorize the tile , probably I need to change something, or maybe imagemagick doesn’t colorize the white, however, looking at some very bright colors (e.g. VIM), probably the gray tile is not affecting the result and the bright details on top of the tiles are still visible (see dock icons)