Black oxfords want a black belt. Brown derbies want a brown belt that is close in shade, not a perfect dye match. Cognac and tan can sit together. Black and brown should not.
A braided belt belongs with loafers and casual trousers, not with a cap toe. A polished buckle belongs with dress shoes. Suede shoes look better with a matte belt than a high shine strap.
If you only buy one extra belt this year, make it the color of the shoes you wear three days a week. That single match does more than a drawer of novelty buckles.