In a few years a white roof would be green on the north side of the house out here. Moss grows in the darndest locations.
Definitely on the west side... my old cabin on the east side had a 40 year old white metal roof... I replaced it this last summer with a "white" raised metal seam roof. The general dryness on this side kept the moss and green away over the years. It stands out some but keeps things cool in the summer. Everything else is the typical green or red roof with a random blue around me.