Strange orange or light marks on towels are most often caused by benzoyl peroxide, a common acne ingredient found in products like PanOxyl, Clearasil, Neutrogena, and prescription creams. While effective on skin, it is “a strong oxidizing agent—meaning it can act a lot like bleach when it touches fabric.”

On dark towels—black, navy, or charcoal—the chemical breaks down dye pigments. As a result, fabric may turn orange, yellow, or pink. The reason is simple: darker dyes fade first, exposing lighter base tones underneath. A quick way to identify the cause is this: “if the mark is lighter than the towel, it’s likely bleaching. If it’s darker, it’s probably a regular stain.”

These marks cannot be removed. “No detergent or scrubbing can restore color that’s been chemically stripped away,” because the dye itself is permanently destroyed. In some cases, washing affected towels with other clothes can spread leftover residue and damage more items.

Although benzoyl peroxide is responsible most of the time, other factors may cause discoloration. Rust from old pipes can leave reddish-brown streaks. A common bathroom bacteria, Serratia marcescens, may create a pink film, but that usually wipes away with cleaning.

To prevent damage, use white towels when applying acne treatments, rinse your face thoroughly before drying, or consider alternatives such as salicylic acid. Towels that are already discolored can still be reused as cleaning cloths or gym towels instead of being thrown away.