I'm worried about my ball python?

I use Repti Bark too and yes, it can temporarily stain a ball python's skin If the Repti Bark has been soaked. You may notice that the stains are the same color as the Repti Bark. Sometimes the dust from the Repti Bark can get trapped in between a snakes belly scales and if this happens when your snake goes into shed, the Repti Bark dust trapped in the snakes belly scales will become damp and sometimes gooey because it mixes the fluid that builds up between the snakes new and old skin. This, and the classic pink belly, common at shed time, will also give the appearance of stains.