I'm trying to piece together a cheap cowboy outfit for my son's birthday (he will be 4). Does brown go with black?

I have found some great outfits I think he will like. He is very particular, and what I mean by that is he has strong feelings about what constitutes girl’s stuff and boys stuff. He thinks that the cow print items look like girls stuff, etc.
It’s been easy to find individual items, but not all in one color. I know of a certain pair of boots and a cowboy hat he wants, which are black.

Would a darker brown cowboy outfit go with that? I’m a little out of my league, and I want to show my wife that I can pick out clothing type stuff for my boys that shows some taste. Any help would be appreciated.

Thank you for your time.