Why is your underwear brown?

Underwear can appear brown due to various reasons, such as staining from bodily fluids, improper washing, or wearing them during activities that lead to dirt accumulation. It might also be a result of fabric dye fading or color bleeding from other garments. Maintaining proper hygiene and washing practices can help prevent these discolorations. If the brown color persists, it might be time to replace the underwear.