To make a place that makes you feel as if you just went diving, paint blue walls, add coral reefs and fish, and highlight oceanic . If you don’t want all that blue in your room, you could have a white wall and then add some seashell decor to accent your oceanic, deep blue sea and create a beautiful under-the-sea room. Exhibiting oceanic life is a perfect way to create, design an underwater themed interior and highlight the beauty of the deep blue sea.