I don't think the match belt and shoes has to be, or even should be, an exact one. It's more a question of combining like with like. After all, belt and shoes are separated by some 3 or 4 feet (depending on the length of your legs). Also the color of your shoes is likely to change. Through wear and polish, lighter shoes are bound to get darker (or acquire patina), while a belt, who might get a bit of polish once in a blue moon and is not exposed to the weather, stays more or less the same.