How to Remove Yellow Underarm Stains?

To remove yellow underarm stains, which are caused by the aluminum in deodorant, wash the garment as soon as you notice the perspiration. Try to air dry or sun dry the garment. You can make a paste to treat it by mixing peroxide, baking soda, and water in equal parts. Darker colors can be washed with a cup of white vinegar in addition to detergent.