I became aware of the problem when my favorite grey hand towel developed an odd neon-orange stain. It wasn’t your average stain; it appeared nearly fluorescent, as if a highlighter had been used to mark it. I washed it thoroughly, thinking it might have been a forgotten spill or rust, but the mark persisted. More towels got discolored over the next few weeks, giving my bathroom a strange pumpkin-orange motif.

Benzoyl peroxide, a common ingredient in acne treatments, was found to be the main culprit. In contrast to ordinary stains, it eliminates color by bleaching the fabric dye. A permanent orange or yellowish patch is the end result, which is particularly apparent on towels with dark hues. After using skincare products at night, I discovered that the stains matched the places on the towel where my hands and face touched it.

Orange staining can also result from water that contains iron, like well water. After washing, fabric gets tiny rust-like specks, especially on whites. Ordinary detergent is ineffective; however, by neutralizing iron before it penetrates the fabric, rust-removing laundry additives can prevent or lessen these kinds of stains.

Unexpectedly, some self-tanners and hair products may also be at fault. Even after towels appear dry, the pigments in “warmth-enhancing” shampoos or tanners may rub off when your hair or body dries. In my case, the shampoo was the reason why my hair towels had subtle orange stains even though I had never used self-tanner.

If you unintentionally wipe your hands on a towel after using cleaning products that contain bleach or hydrogen peroxide, the stains may remain. When a friend was transferring cleaner residue from her hands, she mistakenly believed that her washing machine was the cause.

I now wait for products to dry, use white towels for skincare, and save older towels for hair care. By figuring out the stain pattern, I was able to solve the mystery and preserve my linen closet.