The most-loved color in America? It’s blue. Approximately 35 percent of Americans pick it over other colors of the rainbow. That preference could actually be innate. Our ancestors were naturally drawn to blue for survival—it’s the color of water.

Color has a profound impact on how react to our environment. Part of it is due to our social, cultural, and personal relationships to color. But a great deal of our response to color is rooted in history and deep within our brains. Red, for example, has been proven to increase heart rates, a response connected to cavemen days of fire and alarm.

Yet scientists say there’s something even deeper happening when we respond emotionally to color. The way our brains respond to light and the electromagnetic energy of color can have a real physiological impact. That’s because light—or the color spectrum—can affect the brain's neurotransmitters, chemicals that carry messages from our brains to our nerves to our muscles.