unzip your map, then move the zip file somewhere else or delete it
colors of map territories are in the “map.properties” file
colors of units are whatever unit image is in the /units/nation-name folder. use any paint program to change the hue to the desired color.
unit placements are located in the “place.txt” file. you can change these using the triplea map maker utility. to run the map maker utility, open triplea and then select “engine preferences” then click “map maker”
in the map maker, read the stuff first then move to section 2 and select the “placements” option (manual, not automatic), then load the existing placements using the load menu option. after loading them, you can change them then save it.
all of this is in the help documents that come with triplea, btw