My son bought two new white shirts and assumed he could use bleach. They are now yellow. What can he do?

Let me guess--the shirts are cotton, but also contain a small amount of spandex. Or maybe they are polyester sport shirts that also include spandex. Unfortunately spandex will yellow when laundered with any product that includes sodium hypochlorite (the bleach active in Clorox^® Regular-Bleach), and now your son has first-hand experience with why spandex is on the "avoid bleaching" list, along with wool, silk, leather, and mohair.  I wish I had better news for you, but the color shift is permanent. I think it's terrific that your son is doing his own laundry, and that he uses bleach for his whites--now he has a very good reason to incorporate checking care labels to into his laundry routine. Thanks for writing, and I'm sorry I couldn't have been more helpful.