I normally try to roughly stick to the rule that if I wear a brown leather watch strap, I try to wear a brown leather belt and shoes as well (not always matching the exact shade, but trying to get it close). If I wear a steel bracelet I obviously can't match it to anything but that's fine.
Recently I got this really cool dark green shell cordovan strap that I've been wearing with my Sinn 103. In some lighting it almost looks black but in direct sunlight it's a distinct dark shade of green.
My question is: how do you guys handle odd color straps that you could never match to a belt and shoes? Do you think it looks ok to wear my new dark green strap with brown or black belt/shoes as long as I'm not wearing a suit? What do you think is acceptable to wear a green strap like this with?