Colour change on towels... Any idea?

[EmreMusovi]

Dear sirs,
The towels i use consantly change colours. i dont know the problem.

My setup is occitane cade rich cream with simpson badgers also i use verdon moisturizer and face wash.

after shave i dry my brush first on towel.

1. Can badger brush (cleaned with vinegar and detergent) cause this?
2. Can potassium hydroxide on the cream cause this?
3. Can face wash cause this?

Or any other ideas?

Thank you