I actually have a titanium(silver) yeti(510-sometimes I guess called a cylon) with a red led, but I also have a few silver batteries with the blue led. I have the silver atty's. However, I mix and match, my girlfriend has a black with green led, and she likes all the led colors(blue, purple, red, green). So sometimes I'll use a silver battery with a black atty or vice versa. It would be nice if you had a few silver(titanium) batteries and atty's to choose from. But that's up to you. My friends and coworkers all have the black with either the blue or green leds. I don't think I've EVER seen a white 510 except in pictures.
I always use the black carts(of course). I exclusively use the manual batteries. I've heard from everyone that manual batteries are superior in almost every way. I bought a cheap(non-510) auto battery kit once(off amazon) and the cut off sucked,also it failed less then it worked so I sent it back.
So I guess the answer to your question, for me, would be Black or Silver batteries and atty's (with pretty much any color led's) and black carts.