No Blue Light, Please, I'm Tired -- Light Color Determines Sleepiness vs. Arousal (image) PLOS Share Print E-Mail Caption The color of light matters: blue light keeps mice awake longer, while green light puts them to sleep easily. Credit Flickr user Pilottage. License: https://creativecommons.org/licenses/by/2.0/ Usage Restrictions All figures and photographic images will be published under a Creative Commons Attribution License (CCAL), which allows them to be freely used, distributed, and built upon as long as proper attribution is given. Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.