It would be great if the colour pallete for apps could be turned on on the homescreen but the option to turn it off on the apps screen otherwise it doesn't work as well next to unsupported apps. (Or force apply to all apps using something like the colour swapper system found in photo editor?)
Very good suggestion to raise this about needing a way to force the colour pallette on to 'non-compliant' apps. At present, the effect is ruined as your screenshot clearly shows. I'd thought about using the accessibility option - "Colour filter", but that's not a very satisfactory solution.