What color "marries" well with a soft gray?

If you love the soft gray of the lower cabinets, why not do the same with the uppers? I would paint the ceiling a flat ceiling white and the walls either a soft yellow or a soft acqua. You might also consider what color your appliances are. You could also possibly use a "griege" color on the walls to tie in the counters, unless you plan on replacing them as well.

Teal.

you need a color on the walls that is not the same as the cabinets you can go one or two shades darker or lighter or even go with a gray/white for walls and white on ceiling

if you go to any place that sells paint you can find colors that go with the paints you already have by looking at paint chips too. I buy the small cans of samples to see what works best in my lighting etc

Sherwin Williams Sea Salt would be a nice color. It's a bit of blue & green but still a neutral. Whatever you choose, go with a sample first.

Mallow yellow color and white.

I would choose yellow.

Yes, totally agree with yellow. But neutral shades would also be good for that. Just be sure to have your sample first.

A light yellow would look nice but not to light put some color in there

Your personal taste/ decor style might dictate your choice. Some folks like bold colors some neutral.

I personally find browsing awesome visuals on Houzz or Pinterest web sites to help collect some ideas to consider/ exclude others in aspects of color choice and styles for decorating and refurb applications.

And

Lighting can be can sometimes change your paint color choice. We wanted to paint it a two-story foyer and chose a perceived beige tone paint and it turned out to be a peachy beige tone with the actual lighting.

Gray choices can be blue, purple, pink, greenish undertones.

The little sample jars could be very helpful to prevent a miscalculation and a waste of time and energy.

A few five dollar jars of paint to apply the color samples on your wall could be a good investment to narrow down your choices with your existing colors fabrics and lighting. Best wishes in your decorating adventures, sometimes making the choices is the most difficult part.

The type of lighting that you have in a room can change the perceived wall color.

What kind of lighting do you presently have in the kitchen?

If you are planning to paint, I would recommend to first change the bulbs to LED, or change your fixtures to the new integrated LED style.

Most colors work well with gray and cream. Considering your only light is a north window, you should get some larger paint chips, tape them up and check the color at various times of day. This will narrow your choices down.

Light off white

For a kitchen I would go with a white with just a tiny touch of gray in it so it doesn't look stark and clinical like.

If you are still in doubt go and get some paint strips and hold them up in different lighting or times of the day. See what you like and go with that.

Here's a post that might help https://www.architecturelab.net/colors-that-go-with-gray/

Ceiling definitely White, Walls off white, yellow or pick out a color in the countertop

Go to Sherwin Williams or Benjamin Moore they can help you.

Crisp white, grass green, pastel pink and deep teal would definitely compliment soft gray.

Hi, White Ceiling and maybe Tangerine or Turquoise on the walls or even lettuce green.