Blue Cheese has gone bad?
As explained in this Wired video Gordon Ramsay answer twitter questions Blue cheese can't go off.
What it actually can do is turn from blue mold tint to green. 

If you search for Bleu de Gex you will see that the cheese is in fact yellow and mold is greenish. 

The only thing that would point to bad cheese is it's taste. If the cheese taste ok than it's ok.