Since you've tried the over the counter method, I would agree with Bobbi. Hire a pro. Those sinks are so pretty refinished to their original state and a pro will give you a finish that will last the rest of your life. If you can't find anyone listed in the phone book, ask around at a hardware store.

Upholstery and egg crate type foams will not be rigid, and may not be flame retardant. EPS and XPS construction insulation foam are lighter weight, more rigid, and could be covered with batting and fabric. They come in 4'x8' sheets, but can be cut with a utility knife into smaller sizes. They are available from a big box home improvement store like HD or Lowes. Not sure if they are flame retardant. Depending on how large a piece you are mounting, I would think they may be light enough in weight that they could be mounted to the wall with 3M removeable hangers of some sort.

I want it in a combination of golden.it is in U shape. Kindly suddest colours

Simple! Avoid paint! Simply buy 2 sheets of laminate (one for front and back each) that matches with the rest of your doors, and paste it on the PVC door using a strong adhesive (HeatX by Fevicol, or any other alternative). Enjoy! (Note: This solution can work only if there are no undulations on the peripheral frame of the door) I hope this was helpful.