The retiring coolness of a rich blue and the flatness of the black are going to push and pull against each other, forming a marvelous core tension around which to base a look. Browns, taupes and neutrals are hot with these shoe colors. Grays? A miracle.
Just look at Pour La Victoire's "Ophelie." This is a brilliant shoe. It has a soft, deep indigo suede body clad in the hard shell of black patent with sawtooth edges. A winged captoe with punching is a nod to the spectator trend. Triple patent straps with sueded buttons feel modern, but also remind us of frogged military jackets. And a four-inch, wrapped leather heel makes them just plain sexy.
The spectator and military aspects give this shoe a masculine spirit that makes it ideal under a wideleg wool pinstripe dress pant in black, navy, gray or taupe with a smartly tailored white blouse. We also have visions of the Ophelie paired with a sexy pencil skirt in gray. (And may we recommend Bill Cunningham's slide essay on New York City pencil skirts?)
You can take this in a similar direction with shoes that balance the two hues. Jessica Bennett's Jilt in Blue Patent is such a deep lacquered blue that it shifts into fathomless blacks as the light plays off its gloss.
The concept of "black" is made deeper by the punchy richness of the navy, a sense of depth reinforced by the patent coat. Blacks on their own can be mercurial - some warm, some cool. They tend to flatten and turn green under lights. Blues keep things dark and vibrant, sometimes looking more lustrous and "black" than the black itself.
Blue and black combinations are the slant rhymes of outfit co-ordination. They don't quite dovetail and this mismatch resonates. That gap between them is exactly the kind of sprezzatura we love -- it signals your confident ability to put together a knock-out ensemble, to be just a touch off and therefore right on target.