Blue light beats bleach for yellow stains

Breakthroughs, discoveries, and DIY tips sent every weekday. Sweat stains are a white t-shirt's worst enemy. Unfortunately, that notorious fabric yellowing is often unavoidable due to the combination of oleic acid, squalene, and other organic compounds found in your skin oil and sweat. Factor in a chance encounter with natural food pigments like the carotene and lycopene found in tomatoes and oranges, and it's probably only a matter of time before you'll need to break out the bleach or hydrogen peroxide. Even then, the results are often unsatisfactory for your (once) vibrant white shirts.