The basics of this is that you need to do routine cleaning, especially the filter, to avoid the head from going brown in the first place. If the head has a lot of buildup, you will need to also unscrew the black ring and silver plate and then wash the inside of the head with a clean cloth, natural soap and water.If it doesn’t come off, it is possible it’s on the outside and is a stain from hair color. The best method is to use hair color remover to remove the stain.