Another very popular gray to try is BM Gray Owl. Another is BM Stonington Gray. You need to paint sample boards and see how colors reflect the light in your home. Look at them during all parts of the day and night. Sometimes you love a color in the day and not so much at night. Others transition nicely.

Will not be changing carpet anytime soon, unfortunately (at least another year for sure). I will be adding rugs. The room is actually pretty decent size. Bed just takes up a lot of space because of the sleigh headboard. I will include pictures from previous owners since that's what I have readily available in my phone.

Guest rooms are a great place to experiment with bold colors! Wrap the walls in the cozy dark color and add color in accent pieces like art and pillows. Keep bedding simple but layered for a lush cozy look.

The modern farmhouse trend of white shiplap feature walls sounds like a version of what you are asking for. Not recommending shiplap, as that was done to death, but it would give you a sense of the effect of different texture/same color. I think texture (or wallpaper) would work better than color, because the way you see color varies from wall to wall with the light. So the difference in paint colors would need to be different enough for it to look like more than that normal variation in how the same color looks on different walls of a room. I'm not sure if you can get enough contrast with whites. Maybe if your definition of white includes sufficiently off whites. Something like white grasscloth wallpaper could be a nice accent. Or a paintable textured wallpaper.