James -- Given the choices from that particular vendor I think my vote would be the taupe color for your white car. I don't think you would see any of the blue interior when the cover is strapped in place. The grey looked good on Tom's tunis beige car.
BTW, my red WeatherShield cover ($79.15) squeezes down small enough that I can stow it in a zip-lock bag, ~9x9x1".
Tom in Boise
'71 280SL 4-spd, signal red w/lt. tan interior, restored/enhanced