I like the darker strap because of the white accents, but it doesn't seem right for that watch. I think that you have made the right choice- going with the lighter, redder brown offsets the face color and makes it pop a bit more. I think if you went with the darker strap, particularly with the accents, the strap would take some of the attention away from the watch, and a beautiful watch like that one deserves to be seen!

Although they are both nice, and I don't think you could go wrong with either. Had the watch had white numbers or more prominent white/light colored markings then I think the darker strap would have complimented it well.
Def