I imagine that the composite props are offered primarily in white so that they are the least affected by radiant heat, though one of the MT's we bought was a beautiful grey with yellow tips. The MT I have is white from the factory, not my first choice, but okay. I less favour the angled red tips and stripes, the angle defeats the purpose to make a sharp distinction of blade to tip during rotation. Other than considerations of longevity related to absorbing heat from sunlight, and black faces to reduce glare to the pilot, I doubt that the colour matters much, other than it would be wise to have some contrast between the blades and the cowling to reduce the risk of someone not noticing the blade, and hitting it while moving around the parked aircraft.