Introduce more color options for cards. Maybe event allow users to paste a hex color code?
I agree it would be nice to have a few more colours and maybe even two-tone card graduated colour option but personally its less distracting to have a limited subset rather than almost infinite set to fiddle with. Perhaps a user defined pallette of say 30-40 colours? .. or maybe a well thought out ‘Scrintal’ base colour set supplemented by an additional user defined set?