I was just googling around for rooms with little natural light, and I ended up looking at a lot of finished basement or basement apartment interiors and also high-end hotel rooms. The ones that were the most pleasant and inviting (where the lack of natural light was not a noticeable deficit) had kind of a lot going on. Not in an overwhelming way, but those rooms had curtains and wall treatments and knickknacks and area rugs and artwork -- millions of little decor pieces and several layers of decor interest in most areas of the room. In particular, there were a lot of different textures in most of the rooms. It makes sense now that I think about it -- basements and hotel rooms are very bland rooms -- usually no architectural interest of any kind, including lots of big windows and natural light and moldings and all that. Which means the room isn't really pretty on its own. To make it pleasant and charming anyway, you need to bring in a lot of things that are pretty by themselves. And you need enough of them that you don't really notice anymore that the room's bones are bad. So your home, being a house, is likely a lot better than the average basement, but it still suffers from the same lack of natural light. This leads me to the conclusion that, while I also generally prefer a clean, modern type of design in kitchens, I don't think it will suit your house. It will just be so quiet and minimal that your eye will have plenty of opportunity to notice how dark the room is. Like a plain person forgoing makeup and accessories and wearing a simple beige shift. That kind of simplicity works well for the great beauties of this world, but the rest of us look better wearing cute earrings and mascara. However, on the upside, with all the professionally-designed basement spaces I just looked at, it didn't seem to matter at all if the actual elements in the the design were dark. Usually, there was a mix of dark and light. The bigger thing seemed to be that ALL of those rooms had a lot of lighting EVERYWHERE. Pin lights all over the ceiling, lighting on top of cabinets/soffits that diffused on the ceiling, pendant lights, etc. So: 1) I'd mentally set aside a big part of your budget to add lots of lighting. Have under cabinet lights, above cabinet lights, cans, pendants, a chandelier, in-cabinet lights -- whatever. Go nuts. 2) I think you are on the right track with a walnut floor. Walnut has a really interesting grain. It is thoroughly beautiful in its own right and will layer beautifully with anything else you add. Natural materials in particular are great for adding interest without seeming overwhelming or busy. 3) I would not repeat the walnut on the cabinets because, again, I think the super-layered design approach works better in low-light rooms. Cabinets just another opportunity to add interest, and you should take it. Make them a different color or painted or whatever. Also, think about something other than slab. Your floor will be flat walnut. If the cabinets are also flat walnut, then then that is EXACTLY the same thing. Here is an example of a kitchen with a lot of interest (cool tile floor, two cabinet colors -- one that is interesting and bold, glass cabinets with unusual glass, open shelves, unusual cabinet pulls, feet) that still has clean lines and isn't crazy fussy/busy: That is the kind of thing that will hold its own and still look pretty and charming even in the dark months. Also, it would look great with walnut. :D

I forgot to mention I also have three different countertop materials. This run is vintage cabinets with Shaker doors, black marble (Karin, GW stone expert says it's limestone): Uppers and sink cab in this pic are from the old kitchen. New drawers have slab fronts, and trash pull-out door (to the left of the DW) is a new door. Recycled epoxy resin lab table tops: Old uppers, new slab drawers, new doors above fridge: The drawer fronts and cabinet doors to left of fridge are re-used from old kitchen, added to new boxes. Cabinet over fridge is new. This pic is before ceiling trim: Long shot, after ceiling trim was added. Island painted black, with carrara top, taken from DR: China cabinet in DR matches vintage cabs in kitchen, painted wood top:

Have you looked at the stone patterned engineered tile, like Alterna (made by Armstrong), Supreme Elite, IVC or MetroFlor ? I do think they can look very good against natural wood -- because they have more substance and a different finish, they look much better than any sheet vinyl and many planks, also are warmer and more comfortable than tile. There are several other brands. I have a (now discontinued) Metroflor product that I think looks really nice next to my old red oak floors. You do have to be sure that the tones are compatible with your wood. I have seen some wood grain vinyl planks that are really lovely and durable, but to my eye they just never look right next to real wood -- especially an older wood floor. Have you considered cork?

I'm just doing the cushions so I can save as much money as possible and likely using a synthetic leather, a local company uses makes this commercial grade poly synthetic that is incredible and super cheap. My old couch (at the top) was that product and it blew my mind the wear and tear it could endure lol obviously its not identical to leather but it had a great feel to it and look. I hate that I hate sitting on my couch 🤣 ya maybe I'll wait a little longer before I jump the gun. Who knows really. But I like the idea of tufting (based on what Google says). The loft looks comfy and is but I've had tufted and it really wasn't too bad and I'm sure it'll be even better with how fat these cushions are. I'm just doing the cushions so I can save as much money as possible and likely using a synthetic leather, a local company uses makes this commercial grade poly synthetic that is incredible and super cheap. My old couch (at the top) was that product and it blew my mind the wear and tear it could endure lol obviously its not identical to leather but it had a great feel to it and look I hate that I hate sitting on my couch 🤣 ya maybe I'll wait a little longer before I jump the gun. Who knows really. But I like the idea of tufting (based on what Google says). The loft looks comfy and is but I've had tufted and it really wasn't too bad and I'm sure it'll be even better with how fat these cushions are. I don't have the room for a recliner yet but the plan is to have a house with even space for an accent chair. Maybe one day! So just to sum up, that slate colour in leather (or fabric) is passable on the couch? Talk to a professional about tuft vs loft. Be patient and see about if the fabric calms down. Yes?