All Fomapan 120 films have a blue/green antihalation dye. It's the only type of film that will color my replenished Xtol ANY color, and it's actually kind of cool to pour it into the beaker prior to processing and see its unique color.
As has been said, the film has lovely qualities from a picture making standpoint, but it handles kind of wonky. It likes to curl, and the backing paper is like fine sandpaper, and I honestly worry about putting it through my cameras sometimes, afraid it will be abrasive on the equipment.
A presoak will remove the antihalation dye, but the dye doesn't adversely affect your processing. I can see no change in results whether I presoak the film or not, so I just don't.
Ian's suggestion that the film might not be fully fixed is a good one. And please do handle this film with care, because it does scratch easily.