I have recently used OneTime at the recommendation of someone with a little more experience with it than me. It comes in clear and two colors. But it needs UV exposure to cure. They recommend 8' overhang or less.

Part of the color changing is exposure to UV, so while it may not gray, it will probably change color.

At $80 a gallon, OneTime's not cheap, but you don't need to reapply it every year. You only need to apply one thin coat. A gallon does about 400 sq.ft.

Another place to look is in Consumer's Reports. They regularly review deck treatment products.

Here is a link that might be useful: http://www.onetimewood.com/

I have a redwood fence about four years old. I used the clear Thompsons sealer and the fence turned yellowish gold. Is there any sealer that will retain the redwood color when applied?

Thanks,