The world's most expensive color is ultramarine blue. Here's how it's made using traditional methods.

Blue is the color of the ocean and the sky, and considering blue's color symbolism, it makes sense why this color is associated with calmness. In fact, one survey found that blue is a favorite color ...

Every other Friday on Morning Edition, the Outside/In team answers a question from a listener about the natural world. For the past few weeks, we’ve been tackling queries on the theme of “blue.” What ...