Yeah as far is the colors gos, lamb invented a program, maybe it's in the nerds post in mods called Paulette editor.
You will need to download that. Adjust the colors 2nd and 3rd row from bottom. Save as a .ppl so if your doing forest it would be forest.ppl.
You will need win mpq to open the war patch.mpq. Then add the forest.ppl file
You will have to use the same data that is there so bg/unit/. And it will add the forest file. It's not too tricky but does require minimal learning. If you want I could re do some colors as well for your eye sight. Give me an idea which colors collide for you and i can try to do something.
Also. To add more players would require a new engine for the game or an overhaul to the one we have. If you understand coding, you could help in mods forum
Thanks
Incos