The siding product used here is/was called Cembonit, the color is integral to the product rather than a paint, the color is called "flint". While Cembonit is still available it's now used in very large quantities (malls, etc) and shipped from Europe. .
It's possible to get a similar product from the former US manufacturer under the name Sil-LEED but they no longer have the "flint" color.

I like the wood here. What color is it exactly?

This is western red cedar with a clear stain.