My first instinct was tile exactly because of how labor intensive this would be but then I began looking at all the color variations. I would think tiles would have more consistent coloring so this could definitely be timber. It seems too "imperfect" to be man-made material. As someone else said, "tricky."

Very unique. Hope you found it!

Silk would be interesting, not to mention elegant. As for paints, the Silver Illusion appeals, but it might throw green (not sure). I also agree the Tranquil Retreat is a good one. I'm wondering how big the feature wall is, and what is going on this wall, eg TV, fireplace, large artwork, etc.?

Looking at the attached photo you can see compared to close to the wall the floor tiles are streaked with white stains. I have tried using vinegar and scrubbing brush and also other cleaning products....