I have a different white for my cabinets and my trim. It's fine as long as the two colors work together. My trim color is slightly creamier and my kitchen cabinets have a slight green tinge to them. You can see the difference by the windows.

There's no rule really dictating what you do. You can match your ceiling to your crown as we have done in several rooms now. In our case both ceiling and trim are SW Ivory Lace (which is similar but I believe even darker than Creamy) which really warms up the room and looks good with the generally darker wall and wood finishes in our house. The semigloss on the trim and the flat on the ceiling ensures that they don't completely blend in. On the other hand you can absolutely do a different ceiling color. But if you do I would test out how both look in your space to make sure they are compatible. Before we repainted much of the trim in the house was even more cream (similar to SW Antique White). The ceilings were all closer to a Pure White. The result is that the trim ended up looking yellow. So if you switch to another white, make sure it is still sufficiently on the warm side of the spectrum. Or a third option, as in cpartist's house, try a color. If you aren't feeling that bold it doesn't have to be that dark. It could be the same hue as your wall color, but a shade or two lighter, as long as it is still a shade darker than your trim. Cabinets can absolutely be their own thing separate from the trim or ceiling. But if all are white again refer to my second point about ensuring that they are compatible. Our cabinets happen to be BM Shaker Beige.

Thanks all! Yes, we have a hallway that I believe has Acadia White on the walls, and there is definitely a cream vibe going on there--one reason I'm a little reluctant to do the walls in the new bath with it against the tile. I had Navajo White on my list to check out, and have added Glacier White too based on looking at the Chroma values, though I think I want to go lighter than the trim vs. darker. (We have Edgecomb Gray in the existing bath and I like it against the tiles we're using, but it's definitely a gray, so need something lighter than that.) The room has a south-facing window with LED lighting (some in a bathroom fan where I don't think we have much control over color, and then wall sconces where we do).

It’s generic. My store took 3 matches to see if they could get the same reading twice. They did, and then tested it three more times just to try to be consistent.