We also used Azek as trim with our pre-painted HardiShingles and are glad we did. Our builder really liked working with Azek since it's light-weight and so consistent (no knot-holes, etc.). He even did some bending of it, although that was quite a challenge! Although it technically doesn't require painting, we painted it with a 50-year BM exterior white paint so it would match the white of some of our decorative trim pieces (brackets, crossheads, etc.). We also caulked the nailholes, although they weren't as obvious as we expected because our builder used smaller nails. We're hoping the Azek will never need to be repainted! By the way, we were very glad we got our HardiShingles pre-painted and we didn't have any problems. They were painted by a company called Weiss who gives a 25-year warranty. Weiss has a nice range of colors or will paint a custom color. They're a good company that stands behind their product. Here's a photo showing some of our Azek trim next to HardiShingles. Even the flower box is made from Azek! I should mention that the paladian crosshead in the photo is not Azek. It's by a company called "Custom Decorative Moulding" ("CDM"). We really like CDM products and found their company to be extremely helpful. Their products can be made to custom sizes (as this crosshead was) and they come pre-painted in white - - although not the same shade of white as Azek. P.S. If you decide to paint Azek, our painter learned that it takes special prep first. Not hard, just different.

We have been very pleased with the Hardiboard. No maintenance at all so far and we have had it for about 10 years (? I think). One irritating thing was that a squirrel gnawed on the edge of a couple boards, but not a big deal as it is not really noticeable. We did need to redo our trim at that point. Wish we had gone ahead anyway because I doubt DH will ever bother with it now. Sigh. Oh, and I am beginning to think we may not have the taupe-ours isn't actually as dark as your first picture now that I look at it. I can't remember where I stuck my home improvements binder or I would check. I will look for it. GW isn't letting me share my photos from my iPad these days or I would post one for you. Very irritating. I will see if there are any photos on the Macbook.

https://www.flickr.com/photos/samgarman/19877666091/in/album-72157656124514352/lightbox/ Here is the color scheme photo of a similar house.

I would go with the first two ones, no driftwood.