If you want to be draw attention go with yellow. Studies show it creates the largest reaction in humans and in many other species as well. Yellow is the universal color of nature that says “Look out!”. School buses are painted yellow for a reason.
However, almost no one wants to drive a yellow car. So in that case I’d opt for something besides silver or black which tend to blend in too much on the highway and around town. Most people dismiss colors, but having been a motorcycle rider for a significant amount of time I know how much colors can affect perception. Put a guy on a black bike, with a black helmet and outfit on the road, and put a guy on a bright red bike with an orange helmet and the reaction is much different. When I went from a dark helmet to a bright orange helmet people in city traffic noticed me more, kept a farther distance and were more careful in general. I feel like I just didn’t show up in the corners of people’s eyes until I put the bright colors on.