Black Suits: Black (and patent) or Gray
Navy Suits: Brown (any shade), Burgundy, Red, Green, Yellow, Black etc. The possibilities to what you can pair with navy suits are limitless
Gray Suits: Same things as navy, the possibilities are pretty much endless (depending on the shade of suit). Lighter grays for me, are a bit more versatile, where as charcoal suits head towards the territory of black.
All in all, I have no rules, I generally tend to wear what I feel like. However sometimes I feel like an anomaly, especially in America, and what I believe the average man would be comfortable wearing is:
- black suits with black shoes;
- navy suits with either black, any shade of brown or burgundy/oxblood/cordovan colored shoes;
- gray suits with the same colors as a navy suit.