Would help a lot if you could post photos of your home with the cabinetry in question.

Context is key. Show us pics of the rooms, even if only current.

House renovation under way so all is torn up & covered in plastic. Renderings aren’t accurate in terms of the white in kitchen (it’s actually showing up like repose gray lol) so those are chalk white & den cabinets repose gray. Should I paint them to match chalk white?

I wouldn’t paint the den cabinets unless 1. they are worn and need painting, in which case this is the right time to do it, or 2. you don’t like the color anymore. I find it odd when everything is matchy matchy, but that’s me. I also think of my den (north facing, wood paneled, book cases) as a tranquil, cozy space for focused reading and work more than a bright, light filled office because I’m working with what I’ve got 😂 I’m sure whatever you decide it’ll be awesome.

Oh - I get it now. What you are calling a den is the same space, opposite end of the room. I’d still let each space keep its own identity. It’ll be fine either way.

There is no trend for this! Some people do the family room built-ins to match the kitchen colors and some people use a different color or stain.

In the house I built, I chose to do the built-ins in the same white as the kitchen. In the previous house I remodeled, I chose to do the built-ins in the same mahogany wood as the kitchen.

Do what works best for you and the overall design.

Okay thanks - this is what I was asking & you nailed it. Thank you all. Will mull it over now that I can just decide what we want vs the trend or rules.