Ok I bought a 2012 Sea Doo GTS 130 brand new. I am having the same problem, my seat is staining blue where it should be white and even on the red is staining black. So i noticed that the seat feels really heavy. I ripped the seat off and the fume is socked with water.
This is whats causing this problem. I am pretty sure its because of the non slip material they used on the seat under the drivers butt. I seen online you can order a new after market seat for $175 and you can choice to have the seat completely vinyl.
I have the 4 year warranty, but when i called Sea Doo, they said cosmetic is only covered for the first year. (rip off)
after the first year, you go into the extended warranty witch doesnt cover cosmetic.