Corian is made up from a thick liquid solution of resins and pigments that is chemically reacted, then cast into a mold to create a solid material. You can paint the Corian to a different color, and yes it can be practical. The answer to both of your questions is yes.
If the haze remains, the composite sink may need to be re-sealed. Make a paste of equal parts of baking soda and water and apply that to the surface of the sink and leave overnight. This will help to remove minor scratches, scorch marks, and very stubborn stains from the Corian countertop and will revitalize it. Wipe the countertop surface with the help of an ammonia-based spray cleaner or warm soapy water for minor residue buildups, or with an abrasive cleaner for heavier buildups.
