Does not matter!
Personally, I prefer my characters to be darker, ideally autumnal in shade. A nice deep red like one of the New Monarchy common shaders. I've never been one for my guardians to run around lit up like Christmas trees. Having said that, with that new Solstice armour and their armour lights, albeit still using darker shaders, my guardians are running around lit up like Christmas trees.
My advice would be a yellow/orange/red combination, since that covers you for Mars, Mercury, io and nessus maps. For Earth maps, the shaders from devrim work well. Prioritize camouflaging your head most of all. Hope this works. If it were like in D1, you could change shaders based on the planet or map you are on
Give us Chatterwhite back!