Sound Advice
Pete has given you good advice. Corian is a solid surface material. The color goes completely through it. You can sand and buff out scratches and slight discolorations. A temperature discoloration may or may not come out. If money isn't a problem, call an Authorized Corian installer. They can buff it out or splice a new section. If you want to try it yourself, here are the major steps.You will need:Orbital sanderwet N dry sandpaper 120 220 400 600 1000 1500rotary buffer with wool pad3m fine cut buffing compound & 3m scratch remover or finish glaze.These materials are readily available at any automotive store.I would start with just buffing compound and see if it comes out easy. If not, start sanding. Don't just sand the spot or you will leave a dip in the counter. Once the spot is gone, use finer and finer paper until all sanding scratches are gone. (Keep the area wet throughout sanding process). Now buff with 3M fine then glaze. This should produce a mirror like finish when done.Careful to cover the surrounding area when buffing. Compound will tend to sling all over. Don't be surprised if your repair looks better than the other counters and you end up buffing them all.Good LuckWard