Our bathroom has white Corian countertop with a white Corian backsplash. The clear silicone where they meet has yellow as it has been about 10 years since installation. How do I get rid of the yellow?

You use a caulk removing tool or a utility knife, cut the old caulk, clean the joint and recaulk.

Ellie

Remove the old material. It should be silicone. If the joint is tight you may need a razor blade to get it out. Use a tooth brush to clean with alcohol. When that has evaporated apply white 100% silicone (adhesive or caulk) trying to push it back into the joint.

When you are through applying DO NOT wipe or try to smooth the material out. Allow to cure for 48 hours. Then with a razor knife cut across the joint. That is, with the knife flat against the back splash and tip lightly touching the top, separate the silicone from the back splash. When that is complete you can peal the adhesive from the top.

This will give you a better joint than you originally had and will not have to replace.