Exposing a sweat-like stain on cotton (left image) to a blue LED light for 10 minutes significantly removed the yellow color (right image). Credit: Tomohiro Sugahara Sweat and food stains can ruin your favorite clothes. But bleaching agents such as hydrogen peroxide or dry-cleaning solvents that remove stains aren't options for all fabrics, especially delicate ones. Now, researchers in ACS Sustainable Chemistry & Engineering report a simple way to remove yellow stains using a high-intensity blue...