This very simple tiled bathroom has a coastal feel because of the weathered wood vanity. Not sure if you want to stay away from all natural wood entirely, but the floor on the bathroom is neutral as it the showered tile and it's nice and bright. The weathered wood can be added in a grayer tone if you prefer the cool tones to warm tones.
A good way to add warm tones is with wood colored tile. Not sure how you feel about this but again it's timeless and not so institutional feeling.
Q