We’ve all heard repeatedly how bad blue light is for sleep. Often emitted by electronic devices, blue light has been known to disrupt sleep patterns – but it may not be the only light responsible for that. A research group at the University of Manchester recently published a paper in Current Biology challenging just how bad blue light is. After exposing mice to lights that were different in hue but equal brightness and assessing their subsequent activity, researchers found that yellow light seems to disrupt sleep more than blue. Their hypothesis was warm-toned light (yellow) could trick the mind and body into thinking it’s daytime, while cooler blue light more closely resembled twilight/night time. Learn more about the blue light study and what it means for your nighttime routine.