This would have been a great opportunity to have the space gray with typical black keys and bezel and a silver variant with white keys and bezel (my favorite color combo, since the G5 era).
But since either way you're stuck with the black accents I think the space gray looks nicer but, unless it's not a good indication, the difference between my space gray iPhone and silver ancient ass MBP is relatively subtle. I wouldn't really have much of a preference while ordering one.