good question, I figured the not salmon pads were regular pads with colours in them.
the salmon pads have the special iron compound which makes them that colour.
Thanks for the reply.
My question, though is what is the difference between the three different models of salmon pads; Supra2, Eagle 2, and Mountain Pads?
After I ordered them I noticed on the Sheldon Brown site that he recommends the Mountain Pads, but doesn't mention anything about the differences with the other models.