Most of my leather samples are of the brown variety but tucked away are a few colorful rebels; red, orange, yellow and sage. Shocking!
I took a soft black strip, folded it in half and sewed it down the middle then turned it rightside out. Next I cut 3 squares out of various colored leathers (I find that the backs are more colorful than the front finished sides) then 3 smaller squares out of contrasting colors.
I decided that it would be smarter to assemble and sew each square before I attached it to the black strap. After I layered the two squares I sewed on a metal bead that I tied on the back with a square knot.
The zipper foot was a good choice for sewing on the squares. Use a leather or denim needle and go slowly. You don't want to break a needle or two like someone else I know. (don't ask) Fold the ends over and sew them shut too.