To design a space that makes you feel as though you just went snorkeling, paint blue walls, add corals and fish, and display underwater . If you don’t want too much blue in your room, you might just have a white wall and then decorate with island decor to feature your underwater, deep blue sea and create a magical under-the-sea place. Exhibiting oceanic life is an amazing way to create, design an underwater schemed interior and showcase the beauty of the deep blue sea.