I'd use a solid stain in maybe a gray that's a little bit lighter than the siding.

Sorry it's so blurry, but here's kind of what I'm thinking:

We are partial to the wood defender products.

Yes, exactly. And here's a better example pic I found that I think more closely resembles your siding:

Strange as it may sound I suggest you look into a polyurea finish...yes, it can be done over wood. This is just one of many franchises that offer the product.

http://www.garageforce.com/

No reapplication necessary and it won't fade, peel, or chip.

Never a solid color, semi transparent or semi solid, solid will peel right off. And if that is pressure treated you need to wait a minimum of 6 months as the wood is treatedwith a liquid that will inhibit the stain being absorbed. Cabot or Olympic (from a real paint store) would be my recommendation for a brand.

Installed minuimum 6 months, I used to tell people better to wait a year. That appears to have a greenish/yellowish hue to it which leads nme to believe that it is pressure treated lumber. Alsoo the grain pattern lends itself to Southern Yellow Pine which is more often than not what is used for pressure treated lumber.

Check the ends of the boards to see if there are any tags that will tell you the type of wood. It does look like it is pressure treated. If so

http://www.yellawood.com/resources/care-and-maintenance.aspx