Most of my summer wardrobe is based on navy as a neutral. I have several navy shoes (pumps, flats, loafers) and of course white (sneakers, sandals). My actual boat shoes are pale grey suede.
I used to love wearing taupe sandals with navy, until they fell apart and their replacement was uncomfortable. I miss them less since I discovered cognac. I love how the warmth and brightness complements navy.
Oh yes, red. Perfect with some outfits, too much with others, depends on mood and desired effect.
Almost forgot my mint suede driving loafers -- must pull them out again!
Oh yes and the leopard ballet flats (the combo garners compliments from my colleague who wears Louboutins and Jimmy Choos.) And pewter...
So basically, everything. I haven't mentioned black, cordovan, darker grey, but mostly because in my wardrobe those are shoes for cooler weather. I'll wear them with my navy in the fall though.