You’ve heard the phrase too many times to count: “Once in a blue moon.” But what is a blue moon, exactly? (Hint: The moon doesn’t actually turn blue, unfortunately.) Despite the misleading name, blue ...

You may know them by the acronym ROY G BIV. Together, they make the white light you see when the sun -- the main source of blue light-- is shining. Fluorescent and LED (light-emitting diode) light ...

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 ...