Silicone

Silicone

A resin used in the binders of coatings. Also used as an additive to provide specific properties, e.g., defoamer.Paints containing silicone are very slick and resist dirt, graffiti and bacterial growth, and are stable in high heat.

a chemical that does not let water or heat pass through and that is used to make rubber, grease, and in plastic surgery.

You can paint over silicone but expect it to come off. The best way to deal with it is to remove it completely, paint the surface and then re apply it. Also see paint-able caulking.