I'd be happy to work on this feature if the maintainers think it's a good idea.
Currently, the "color-scheme" parameter in the configuration xml can only choose one of four color schemes. It would be nice if it can also configure individual colors, so that more customized color schemes can be chosen.
I propose to make the "color-scheme" parameter a series of semicolon separated commands, e.g. "black-white; color2: rgb:cc/33/22; ...", where each command specifies a color-set or a single color. This new format would be backward-compatible with the previous format, because previous values like "black-white" would be interpreted as a single command.
Possible color-set commands are same as before: "black-white", "gray-black", "green-black", and "white-black". These commands set the foreground-background colors to existing values.
The single-color commands are "foreground: <color>", "background: <color>", and "color<n>: <color>", where <n> is a number from 0 to 255, and <color> is a color value in the format rgb:RR/GG/BB, which matches the format used by xterm. These commands set the specified color to new values.