I picked up some feeders today, and noticed as I got one out that he is a lovely brindle colour. A little googling told me that this is in fact a recognized colour, but it's not one I've ever seen before. The little guy is really pretty, and he's actually friendly...so I caved and didn't feed him. His excuse is that he's going to be used to scent rats for some of my balls that I'm trying to convert to rats. Mainly it's just 'coz he's purty though. :-P
So how common are brindles? This guy is wild type on his main body, with a golden tan underbelly that comes up his sides, legs, and tail base. The brindling is only really visible on the dark areas.