Probably because it looks a little like gold, I've found that old African brass works well with ancients (see photo). High content Hill Tribe silver, the kind with a matte finish, also can work. Other beads with no gloss can be tried - I'm a fan of black and brown wood disks; also horn and bone.

I think that using blue spacer beads of any kind will make the whole necklace look too uniform and possibly boring.