For trim (with almost any color), I have always used Pratt & Lambert's Silver Lining. If you go to a P&L dealer, they can make up a quart-sized sample (eggshell only) for like $7...it is a great trim color. HTH

With that beautiful acacia floor with its distinctive grain I too would vote for something without too bold a competing pattern. A classic soapstone, or a “mist” (Virginia, Silver etc) honed granite or a soft white marble with gray - any of those would look beautiful. I suspect as geologists that you both really “see” stones for what they are as opposed to the general public’s perception of counters as being simply a field of color and pattern. But a deeper knowledge or appreciation of the material itself is not your friend when getting everything to pair well. Ironically. I don’t find Houzz easy to search, but you might see what you can locate pictures of kitchens with acacia floors as your starting point. I would focus on the choices of counters used first, then cabinet color, and finally backsplash. Re the marrying cool tones to warm ones there shades that are neutral but a paint color still will not tie everything together. You can used the same stone for the counter and backsplash though, which eliminates one matching conundrum. Final thought, don’t use quartz - you are geologists - you of all folk should have real stone.

In my opinion, I prefer cool colors with cool, and warm with warm. That makes for the best unity in a room. Also, if you have too many neutrals, you may not have enough interest in the room. Take a black and white photo to see the contrast. What are your light, medium, and dark colors? What colors do you like? Take inspiration from a favorite piece of fabric, accessory, or wall decor. Here are cool colors: bright white, taupe, ice pastels, bright red, royal blue, emerald green, forest green, navy, black, gray, purple. Warm colors: off-white, beige, tan, brown, olive green, golden yellow, peach, orange, rust.

When there are several different natural lights coming into the room, I go with the one which delivers the most light…so, guessing the light from the slider is the dominate light (West). Try B.M. I know you really want a white for the walls, but with all the different light neutrals you have in the tile and the cabinets, give a moment’s thought to White Winged Dove, as it has a LVR of 76 (meaning not a whole lot of undertone) I think you need to consider your floor tone more.