I'm getting ready to build next spring and I've only read good things about Everlast. Seems to be used mostly on the east coast. The only issue is they do not offer a shingle version which I need. I would like to use the same brand on this house that has shiplap, shingle and board and batten siding for color match purposes. I've also read good things about NuCedar (shingle siding) and Celect. Both of those products are cellular PVC with a baked on paint. There are way too many threads on Houzz regarding how bad the cement board products are. They seem very very dependent on perfect installation and what climate they are used in. I'm in Michigan so I am not messing with a product that likes to absorb water if not perfectly primed.

This house has a similar reddish roof to yours and has warm taupe siding. You can paint the vinyl. Note the trim paint is a gold color, not white. Another color that harmonizes well with brick and red roof is sage: Keep the red brick. It suits the house, the roof harmonizes. Just go a warm taupe or sage green and spend your money on further landscaping in back--beds with a mix of high and low shrubs along your new fencing would give you a green oasis back there.

"I have yet to find a company that makes siding in any shade of purple." There's very good reason for that. The reason the OP's first image of the purple house looks so appealing is because of the architecture and not the color. Get the architecture right and you can paint it just about any color you want. Can you post a few exterior elevations of your proposed house?

So the Accoya would eat up $190K of your $230k total framing budget? The materials cost for Accoya is in the right ballpark, but the installation cost seems rather high. The $3.4/sqft for installed Hardie seems low. I'm a fan of Hardie as it was installed on my house when it was built in 2001 and still looks pristine. Something does appear off with those comparative numbers. Time to sit down with the contractor and: 1) make sure there are no mistakes in the calculations, 2) make sure you are on the same page in interpreting the numbers, and 3) if nothing changes, get an explanation of why the cost to install Accoya is so high compared to the Hardie material.