Q: Apple Watch Sport Band Stain Issue

I have Apple Watch Sport SS with White Sport Band for over a week. I just started noticing the stains on the sport band. I thought it was just some dirt or smear, and I cleaned it with a dump cloth, but it appeared to be permanently stained. Is there anyone noticing the same issues? I understand that it may be easy to get stained due to the material, but just over a week? And I've been using it very carefully not to get wet.