At some point in your life you’ve probably watched a talk show, daytime or late night, and heard one of the guests talk about something he or she did in the “green room.” The first time you heard it you were probably a little confused, but after a few minutes you figured out that it simply refers to a waiting room. It turns out that this is a pretty standard term in the entertainment industry that’s used around the world in all forms of media, not just television. You might think that the term is some sort of artsy way of making something sound cooler than it really is, but the reality is no one is quite sure how the term originated.

Theater historians have been able to determine that the term was first used in the entertainment industry during the European Renaissance, but they are unsure of its original, precise meaning. Some think that it originated from the area where actors practiced their craft, known as “The Green,” while others think it had to do with the color of early theaters. By the early twentieth century, though, it had become a common term in theater for the area where actors waited before entering for their scenes.

There may be a scientific reason for the green room.

Although most modern green rooms are rarely painted green, psychologists have identified green as a color that produces calming, soothing effects in people. Numerous studies have shown that the color green helps alleviate anxiety and nervousness and that it tends to be one of the most positive colors.

Obviously, people weren’t conducting in-depth psychological experiments during the Renaissance like they do today. But perhaps these early directors realized that their actors were more relaxed when they entered the stage from a green-colored room.

So the next time you hear someone talk about being in a “green room,” consider the possibility that just saying the name of the color might help them relax.