Benjamin Moore suggests pairing rushing river with Caponata, AF-650, a very dark brown. You might like it.

@msjoan Thanks. I don't like brown tones. I prefer to go grey tones instead.

I do not think it would be too dark. You are talking about a relatively small wall that will be surrounded by very light walls. I think it would go great with the green of your cabinets. Are you thinking of doing black hardware or light fixtures in the kitchen?
We did a shiplap style very dark blue accent wall on our stairwell wall. It's one of my favorite features in my house.

Oh, and have you looked at Iron Ore by BM? It's a dark gray. I think something more off black/very dark gray would be a less stark look.

Sorry, meant Iron Ore by Sherwin Williams.

Thanks @Amy Lynn I'll check that out. I'll be doing brass hardware but black lights/sinks and faucets.

Hi, I just did my kitchen in BM Black Beauty and am thrilled with the results. It is a warm charcoal black that is quite lovely. It might work for you. Good luck!

I think your color scheme will look great.

Black Beauty is a great look black with no brown tone.

I used Sherwin Williams Peppercorn in my kitchen (white cabinets).

@houssaon Thanks! That's beautiful!

We recently painted an accent wall in BM Peppercorn and absolutely love it. Not too dark and i think it would compliment your green very well.

Benjamin Moore Iron Mountain is a very nice dark grey. It looks boring on their sample chips, but great in the right location. I'd definitely recommend trying some paint samples on your wall to see how the paint works in your lighting. Paint can change so dramatically depending on the direction of the light and what's outside the window. I think most people don't realize how much the colors outdoors influence the color of the light indoors - for example, we're in a neighborhood with many mature trees and the sun shining through leaves brings out any green pigments in paint.

All the interior doors in my home are black Sherwin Williams Cavair Black. i love the look

We are at the end of a 2 year remodel of an open plan ranch with soaring ceilings. We indulged, iron deep black/bronze front entry and originally thought we would repeat the exterior SW Tricorn Black posts in the interior, range hood, interior doors open to living, however while this blends beautifully on the exterior deep black/bronze iron doors, interior it was a no go. An accent wall on a south facing wall however worked beautifully. There are no sure bets here, unfortunately. Good news it is paint, not permanent and relatively inexpensive. I would suggest painting at least a 4X8 on the wall of several colors. If time allows, live with it for a couple of days. It will change as lighting changes. I prefer cooler grays, but even these colors need balance of warms.

I think the black would look good but I’d worry about seeing dust accumulation especially if your shiplap has ridges. (google dust on walls) I have ridges in my kitchen cabinets and they accumulate dust and it drives me crazy. Maybe a deep gray? Both black and gray would look great with green.

What about a very dark green?

Like Sherwin Williams Pewter Green? Or a navy blue?

I painted my lower cabinets Iron Ore. I like how it goes from soft black to charcoal as the light changes. I have it paired with black nickel/brass hardware.