What I did was take a standard black leather kilt belt I had and spray painted it with several coats of brown paint. You may be able to find brown leather dye in a spray can at some automotive supply places. You have to wait for the paint to dry for at least 24 hours before wearing it.

I also converted a plain black sporran into a brown one the same way. Had some pictures posted a while back but they were on my old computer unfortunately
and are now lost.

I think I may be the only one so far to try this. It may sound a bit silly but it works for me and I'll probably do it again in future.

.