I'm not a big fan of black straps either, but, as you rightly note, black is indeed the best colour for the Reverso Rouge. I really did try to find another strap for it, but, at best, it would have been black stingray...
I haven't actually worn my Rouge yet, although I've put a mesh bracelet on it (inspired by another members' earlier post). I'll probably switch back to the original black strap when my JLC folding clasp comes in.
Kind regards