What color should I paint my screen?

I picked up an InFocus LP425z for movies by my campfire and I have a 9' x 12' paint drop cloth that I'm using for a screen. It is a tan color and I thought I could paint it easy enough and maybe get a little better performance from it. I'm not to concerned about getting high quality, but if I can throw some white, silver, gray or whatever color paint on it to make it better, I thought I would.

So what color is best for an outdoor, drop cloth screen?

Thanks

Honestly it doesn't bother me either, I was hoping to gain a better picture and possibly be able to start a bit before it get completely dark (so the kids can watch their movies before its too late).