a) it's not unsupported - ask me to add additional features
It
is unsupported. The only supported thing that's allowed to modify config files is Code::Blocks.
Anything else is hacking, and unsupported, even if it works. If anything goes wrong, it's the user's problem alone. The same is true for editing the XML in a text editor. While this is certainly possible and will probably work just fine 99.9% of the time (yes, I've been doing it myself), it is not supported.
Regarding making a copy of the lexer files, this is certainly a possible approach. To me, either is the same, since I have never had the need to change a colour set, but I could imagine that there are as many people who prefer having just one file to copy for everything. To be honest, I have no idea which is "better", if any solution can be said better at all.
For now, I wouldn't touch colour sets, since it is not dearly necessary and whether or not one favours the present system, at least it works reliably.
The risk of "improving" something that works reliably to a point where it doesn't work any more *cough* *cough* is unfavourable if we ever plan to bring out a release. There are still enough things to fix that
don't work, unluckily.