Altec Valencia bass driver...green original versus black color


As the title states...I have chance to buy a pair of backup woofers for my 846A (16 Ohm) Valencias, but they are the black drivers and not the green. Does anyone have any insight as to if I should stick with the green color for any reason. I believe the black was later production, and other that that, I don’t believe there would be a difference. Thanks in advance.
fjn04
I had a pair of Altec Valencia 846-B's. Latest version of the Valencia back in the day. I believe the 846-B was a 8 ohm version. This might be the difference between the black and green drivers which could quite possibly be a difference in the driver's impedance. Not totally sure on this though.