I'm having a hoot at the moment knitting up swatches and playing with different colour combinations, trying to come up with a group of colours I like together for my next project. I'm thinking a long, skinny striped scarf is the go. Possibly not in garter stitch, maybe in skinny regular width stripes, or big wide stripes, it's all up in the air at this point. And part of the fun.
I don't wear much brown, but I love brown in combination with other colours. Pale or teal blue. Purple (natch). Berry reds or hot scarlets. Even orange, or pink. This sort of warm 'milk chocolate' seems to work particularly well with other colours. In fact, most mid to dark toned browns do. Less harsh than black, they somehow enhance the warm or cool qualities of other colours without fighting against them.
I'm going to try a few other combos and some different stitches until I get a comination that I really like. Fun, fun!