iPod Early generation Earbuds

I wonder if anybody knows the difference between these to earbuds? The first set is a first generation earbud with black covers. The part number is 603-2482. The second set is also a first generation earbud but with gray covers. Part number 603-0679.

I have found both black and gray earbuds in both first and second generation iPod boxes? That is why I have to ask if anybody knows for real? I would guess a lower part number would suggest an earlier model??

Thanks again Jessica, your'e a true gem

Those illusive 1st generations ...your answer made me look into this from a different angle. I actually found a picture on a true first generation pair of earbuds, without the foam. The picture is from Apples "Reviewers Guide" from October 2001. The mesh is different and also the part where the cable goes into the ear piece!