'Traffic Light' Labels (image) Massachusetts General Hospital Caption In the Mass. General Hospital cafeteria, color-coded labels indicate the healthiest sandwich choices (green), along with those designated less (yellow) and least (red) healthy. Credit Mass. General Hospital Nutrition and Food Service Usage Restrictions None 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.