There was an extensive post on this a while back. A poultice needs to be applied to remove the stains. It is called green bloom. Call you fabricator to come out and fix it.

INSIST the fabricator fix it. don't pay him till he does. this is a major blunder on his part using the wrong adhesive. if the "blooms" don't disappear entirely make him replace the tops.

We had the same, it was the adhesive. Info I read here on GW suggested it was pretty normal. It went away within a week I'd say.