As good as the rocket plumes in this game are, they're far from looking as good as real life ones, here are a few ways they can be more realistic:
—Less transparency, more glow for most fuels
—LH2 plume should be more transparent and practically invisible in space
—Aerospike plumes should look more like over expanded plumes
—Aerospike plumes should not be expanding at higher altitudes but instead the plume from each combustion chamber should just be separating from each other