i'm making a dr pepper can shaped cake. what should i mix to get that brownish red color of the can??? please help!!!!!!!!

If you are covering it in fondant I would mix some brown color into the red, or even some chocolate/brown fondant.

The can color also includes quite a bit of purple--more purple than brown I'd say. Do you have a burgundy food dye to start with (I know Wilton offers one)? I'd probably start with that and then start adding a little brown.