Some photos of your kitchen would help. Paint colors can't be selected in isolation.

I really never think of gray giving a " pop". While gray is immensely popular it does not work in every instance. Do you have plenty of natural light and flooring, cabinets, countertops, etc. that will work with gray? Pictures are needed in order to get valuable advice.

Gray paint has undertones of blue, green, purple or beige. It will depend on the elements in your room such as natural/artificial lighting.

https://www.blesserhouse.com/choose-perfect-gray-paint/

Thank you so much guys, my kitchen is being retouched now, so pictures won't really help at the moment. I guess I have to finish everything in it, then choose what grey color suits my walls best?

@Grapefruit, Sorry I didn't mean "Pop" as in colorful, I meant that I want a shade of grey that would give some cool and comfy atmosphere to my kitchen.

@Lil S, The article helped me a lot, thank you so much!