I don't think you could go wrong with either, but I think I'd prefer grey. The thing is that the paver should not be the most noticable feature of the house, but compliment. It is really an impossible question for us to answer since we don't know what the houses look like or the pavers.

But here is a nice grey tone paver that wouldn't be too much even with grey houses.

And these would compliment grey houses:

This paver looks to be more of a beige tone:

Good luck with your development!

Thanks so much for your input..