I am a little confused by the different color decals and choices related to Clean Air Vehicle (CAV) decals and High Occupancy Vehicle(HOV) lane usage. I mean there seems to be a red, white and a green, and I have heard talk of a purple starting next year... For a new model 3 owner living in the bay area (Santa Cruz) what is the best choice or strategy with regard to CAV decal color and choice, etc? Thanks.