It would be ridiculously easy to find out what color for room walls is best for SQ. Simply buy enough poster paper to temporarily paper the walls. Try a restful shade of green, maybe frog green 🐸. Then try black. And white. A medium blue. 🦋 You can try orange 🍊or even peach. 🍑 That would be peachy. How hard could it be? Keep a log. Write it up and send to AES, Psychology Today or post it here, whatever.