I've decided what this needs is a bit of fascism. I'm going to put together a colour scheme based on suggestions here and preserving as much of the existing UCS as possible. I shall then publish it as the start of a thread which will be filled up with maps (not just Worlda maps) using this colour scheme of both OTL and ATLs.
This new Thandean Colour Scheme (TCS) is not going to be forced on anyone but I'm going to push the boat out and see if we can get people rallying around it. People are of course more than welcome to start their own colour schemes.
And to answer the obvious question: Russia will be gold...and green. Stay tuned!
Thank Thande and his lord Ian. I fully support your dictatorial powers