Check out these guys on their military surplus page:
http://www.sportsmansguide.com/net/b...aspx?c=2&dc=74

For day wear, a plain web belt in the OD or khaki or whatever would look fine, especially with a khaki shirt. For evening you could just get a nice buckle and put it on a dark colored web belt or, as you say, dye one a dark color.

The great thing about the military belts is that they last forever.

Keep us posted with photos.