The gray is the problem. It clashes with the cabinets and the rest of the house too. Pick another color and repaint it.

I might paint the kitchen, but, it looks fine in the living room, and it also looks like your couch and rugs etc are all chosen to go with the gray. If you repaint, you may have a lot of things, that will no longer look good. A color to go with your kitchen cabinets, is something in the blues, or greens or aqua shades (light colors) Your counters and back splashes, dont really go with the gray walls in the kitchen, however, the blues, greens or aqua shades will go well with everything in your kitchen, except maybe the bar stools.

The only things that go with gray are pink, or yellow. Especially that dark gray. I'd re-paint with something you like. Gray can be seriously depressing, especially as dark as that is. Um, nothing neutral I can think of (or would want to live with.)

But keep in mind I'm simply NOT a gray person, whether it may be in "trend" or not.

What colour can I paint that wouldn’t clash with the rest of my grey walls and still matches my feature wall?

Most likely a near neutral from the same hue family as the blue feature wall.