Yeah - I was having a hard time finding anything on the net.
But below is what was suggested to do:

IMO, there's nothing wrong with breaking up the facade of your house by painting the samll section a harmonious contrasting color.

White, on the other hand, is highly contrasting with just about every other possible color (I don't know what color the bulk of your house will be), and I would be very hesitant to paint it white. I think there must surely be another more harmonious and less contrasting color that could be used.

What is the color for the balance of the house? Good luck!

Interesting....gives it more of the look of old colonial homes in NE where, with the awful winters, they connected the house to the workshop and eventually to the barn so you could get to everything you needed to without going outside. Friends had a home in NH that was very much like that, and parts of the building were painted different colors so they looked like separate buildings, but very close together.

As the home appears to be 4 linked structures rather than a single family residence, I'd actually emphasize that feature by choosing different but closely allied colors for all 4 sections. Pick a color for the larger section that you like, and then go to adjacent color strips and slightly up or down the scale for the other three sections.

Ocean Pearl for the main larger section.

Squirrel for the small section to the left of the main. (going darker emphasises the fact that it's set back from the main house, and that makes it more interesting)

Koala Bear for the next. It's a little bit browner, but none of the greys are stark bluish greys. They are all more greiges.

And for the last section, darker, and slightly browner again, in Ashwood.

Set it all off with crisp white trim and a warm accent color like a brick red/orange or a purplish burgundy for the doors.

@VirgilCarter: thanks for your feedback. To provide more context, the house will be heather grey on the sidings & white trimmings.

This particular section is on the 'backside' of the house essentially so that's why I wonder what my builder is trying to get @ introducing a bit more 'complexity' in the already hectic custom build process.

@AnnieDeighnaugh - thanks for the feedback. Would luv to see pictures of your friend's place if possible!

Maybe I need to google NE colonial home images.

@hollysprings: appreciate the fresh ideas!
I think that 'cascading down' of similar colors would be quite interesting! Would luv to see if you had any visual sample.

Left structure is the detached garage that appears attached to the other 3 sections because of a breezway cover ( which you really can't tell from looking @ it from this side).

Our colors most resemble - on my PC @ least - to your Koala Grey - hint of beige in there: