Sky Blue Marble Treads Natural Stone background wall Sky blue marble is a calm color, and it represents the character traits of restraint and deepness, modesty and prudence, beginning well and ending well, strict self-discipline, and empathy. When it comes to interior decoration design, blue is the coldest color, so, will the blue decoration look cold and not warm at all? In fact, the blue interior decoration will appear very pure and natural, allowing our thoughts to roam freely in the blue ocean.