Without knowing the actual reason for sure, I would say the reason for the different types of foot pads is simply product development. Between the first production run and consecutive ones sometimes "simple" things like this are changed. If the designers think of an improvement and it's possible to do it "mid season", why not do it? Big things like shape is of course always the same throughout a model year. Boujmaas pads look pre production for sure. Something I've also noticed on m boards throughout the years is that the black-white pattern on the pads may be reversed. My guess this was due to the pads first being all black or all white, then cut and re-aligned to form the pattern which would leave half the pads looking one way and the other looking the other way.
Replacement pads: It may take time, but your dealer should be able to order from your importer should should be able to order from Starboard.
Bottome color: I don't even know which is the "right" one. The one one the web ste might be some pre production idea. I have to go and check what color I have, but I think it is also white-greyish.