It seems like it should be fairly easy, as there are so few that are not dark green. This is my list:
Yellow = US, Holy See, Israel
Blue = Taiwan, Hong Kong, Puerto Rico, US Virgin Islands, Bermuda
Grey = Greenland, Western Sahara, Lichtenstein, Macedonia,
Light Green = Macao, some Caribbean Islands
Yellow = US, Holy See, Israel
Blue = Taiwan, Hong Kong, Puerto Rico, US Virgin Islands, Bermuda
Grey = Greenland, Western Sahara, Lichtenstein, Macedonia,
Light Green = Macao, some Caribbean Islands