Our cabinets are BM Gardenia, a very warm white. We matched the trim to the cabs, including the baseboards. For the ceiling, we went with BM ceiling white, whatever that is. For us it worked out well. The business of "layering whites" has worked out well for many posters on this site. Personally, I think, that except for the ceiling, as long as there is some separation between the whites, you can have almost as many shades as you like. Like you, we also went with a grey-ish color for the walls. Ours is a 50/50 mix of BM Metallic Silver and Pidgeon Grey. If you're looking for a light grey, look at BM Metallic Silver. It was too light for us, but it may work for you. Also, keep in mind that paint is the easiest and least expensive thing to change. Here's a shot of our kitchen and below it, a link to the completed kitchen slideshow. HTH. Here is a link that might be useful: Completed Kitchen

Since you don't see you garage doors when looking at the front of the house, I would think you could do something different with them and paint them an interesting contrasting color. I agree that if they showed from the front, I would paint them the same as the house. Our garage in an ell behind the house (we have a L shaped driveway that goes along the side of the house and then turns and goes behind the house so the garage is not seen from the street) and the doors are painted the same color as the front and side doors: red! The house is a sage green with darker sage trim. It was this way when we bought it, so it wasn't my idea, but it looks good. I will be changing the style of the doors to a carriage house type and will then have to decide about color. But I can postpone that decision for a while :)

What color blue did you paint your ceiling? Do you have any pictures you could share? I want to do the same thing, paint the entire ceiling a slight blue tint. I am leaning towards SW Rhythmic Blue 6806 diluted by 75%. https://www.houzz.com/discussions/ceiling-paint-color-dsvw-vd~5252558

so much depends on the size of the kitchen, how many cabinets fill the space, and the flooring and countertop options. A few photos would help, add in comments, or edit your post.