My builder uses Houzz Pro to plan the timeline and give detailed estimates and daily updates with photos of progress, and provide invoices at pre-agreed key points in the build. This made the whole experience much more efficient and stress-free.
The architect did answer in another of the pics that it is a custom gray. Sometimes you have to dig a little further into the different pics to find a color or source since the designers can't be expected to comment repeatedly on each and every photo.
rogerbob