Put some fun towels maybe an orchid plant and it will look like a spa

With regard to wall color, look at Benjamin moore color gallery. There is a Rhine River that is nice and any of the colors around it or in the grey green category below would be very restful.

I am the wrong person to ask as I am not a purple fan.

however 2118-70 Heaven has a hint of purple and is known for its tranquility

look at the discussion "What color grey Paint did you use" it is a nursery using that color. It will give you an idea