Studio 1458 heatsink help.

My warranty expired. The laptop was overheating. So I searched on the internet and one possible solution was to replace the thermal compound. I am on the process of doing it. However, I realized that the heatsink was also in contact with 5 other parts of the motherboard. 5 of them via a green color pad and 1 via a gray color pad. My questions are:

Are the green pads thermal pads (they seem more for cushion) ? If not, what are the green pads? I must know because one was damaged and I need to replace it too.

Is the gray pad a thermal pad? Can I use thermal compound instead?

Is there a specific thickness of the pads for the studio 1458? Or they are all generic?

Thanks!