The white on a rubber roof is just a coating to begin with. Meant to reflect the sun/heat. Seen many RV's down around the Mexican boarder that are being FT'ed in (but never move) with mostly black roofs and no leaks.
Did my 5'ver last winter with good results, total cost was $80 for two gallons of
rubber roof coating. Time will only tell if it was a good solution or not. Trick is to make sure the coating can handle "ponding." All RV's will have some area that will hold water. Many of those coatings that are water clean up will dissolve if ponding occurs.
Removed everything but the AC. Used a brush to get under it as best I could then roller around that. First thing I did was resealed with Dicor lap sealant to make sure the roof was in water tight condition.