What color do you have on your doors and trim? Because Westhighland is a light color, if you did decide to choose another white for your ceiling; you may want to check out the following because they’d both be bright enough to contrast with the walls.

Would this look good on ceiling also.

Yes.

Haha...painter seemed shocked... How tall is the painter? Or maybe they did think they were painting the ceiling when they gave you the quote? Or thought you wouldn't know they hadn't painted the ceiling? 

I actually like rooms with the ceiling a lighter shade of the wall color, so that it looks like white but is really an extension of the walls. So, while this particular wall color will work for everything in the room, you could also try just a lighter version...if there is one...on the ceiling.

Doors, trim and cabinets will all be stained.

Pros and cons for painting the ceiling “white.” The biggest reason to paint it a neutral white is that you don’t usually have to repaint it if you change your mind about the wall color in the future. If you do want white, you don’t have to choose a cool toned ceiling paint (e.g., SW Extra white is light). Some people don’t like to see a break in color at the ceiling, in which case one color works well. I’m surprised your painter was shocked about painting the ceiling the same color. I would expect that he does that fairly often. Where I live it is very common for production builders and landlords to paint everything the same (and the same sheen). I would suggest a flat paint on the ceiling, though.

There is a lot of light also if that makes a difference.

Westhighland White belongs to the yellow hue family, has a nuance that's bright and chroma more than .50.

It's an ideal ceiling color. Color appearance changes with the angle its viewed. Horizontal Westhighland White (ceiling) juxtaposed to vertical (walls) Westhighland White will reflect off each other and the inherent brightness that comes from its yellow hue family will be an advantage.

Because color on the ceiling normally gets darker and grayer in appearance - due to the angle. It's called flop angle.

Either a whiter ceiling or a matching ceiling works with Westhighland White as long as the ceiling white isn't overly cool. When I pick whites for a home I almost always use the same white for Walls, Ceiling, Trim, Cabinets, just changing sheen. Whites can be difficult to get right and it is so easy to ensure that the whites won't clash if you simply use the same white.

Here are 2 pictures of rooms with Westhighland White walls. One with Westhighland White Ceiling and one with a whiter ceiling.

Not all whites can be lightened by just cutting the formula, but it appears that Westhighland can be successfully cut, so you could do a lighter ceiling and not worry about the colors clashing,

I think it’s fab to paint ceiling same color as wall! But I may recco having ceiling flat and wall cashmere.

@Sarah Kramer you said the doors, trim and cabinets will be stained. So does that mean a stained wood? Will the floor be wood too? Will you have crown moulding at the ceiling? If so, will it also be stained wood?