Today's color combo is black and brown. Whenever someone asks me if this color combo works, my short answer is that they should wear whatever they want if it makes them happy. But my personal preference is to match black with a medium brown, like cognac, or a lighter brown, like camel. Chocolate brown is too close and doesn't offer enough contrast, in my opinion. But again: that's just me. If you like black and chocolate brown together, by all means, wear it!
Here's how I'd work the black/brown combo.
