I ride a KLR and always wear my grey Motoport jacket and black pants.
I alternate days between my 2 FF helmets, 1 is white and the other black.
I believe other drivers give me more room when I wear the white helmet over the black one. I assume because it's more visible, but some others have mentioned it might trigger some reflex in drivers brains "White Helmet = Cop".
I keep a high vis vest in my top box and always put it on when it's raining or when riding after dark, or riding in the woods during hunting season. I believe I should probably wear it more often, but most of my riding is just my 15 minute commute to work on back-roads. I know, famous last words...