If I remember correctly, this issue has been brought up before about a year ago or so. *Somebody had a "green" BFP, and the discoloration was most likely due to the paper overlay fading because of constant exposure to lighting. *If it was hanging in a store for a while, and the store had fluorescent lighting, that could certainly turn a BFP into a GFP. *
I think that the the time the last Green FP came up, the comparison was made to what happens to a newspaper if you leave it out in the sun for a couple of days-the ink turns greenish and fades a bit. *
Just my hypothesis though.
