Tux colors?

jcl4565

Hello all!  My colors are plum/eggplant and sunflower-yellow.  I'm getting married in early october next year and don't know what color would work for the tuxes.  I'm not opposed to dark brown, but I don't think I've ever seen that and don't know how cheezy (or casual for a Sat night wedding?) it will look.  Will black or grey work with those colors or should I stick to brown since it might be a color we incorporate anyway?
Thanks