I've wanted to get Lucy a pink one. Of course I don't want anyone thinking she's a nasty little ankle biter, but all it takes is watching her to see that she's not, regardless of what collar she's wearing.
Lucy can get pretty rambunctious, though, so I don't want her to hurt herself or anyone else with spikes, so I decided I'd get her a collar with studs like this:
Unless the spiked collar was just for closely supervised occasions.
Oh, and on the search for images I saw tons of sites called "pit bull fashion," "pit bull gear," "pit bull store," where they sell crazy spiked muzzles and 98% of the dogs are hippos.
It sucks to be so limited by foolish people, but I would never put a spiked collar or muzzle or harness on any of my Rottweilers. People are already scared as hell of one walking down the street wearing a pink flowery collar.