Would you use the silver with a contrasting band, as shown? Or would you try to get a band that roughly matches it?

It sounds like the colors don't add much complexity because it's just a polycarbonate piece that's sandwiched between the metal front and back. It does add complexity and and there are surely some fixed costs associated with making these and the matching bands. But it's kind of a neat innovation to have a pop of color on the side, matching the band. I think the red one could actually look nice with a plain black band.