I had this same issue with my hedgie when I first got her. The red mucus didn't happen to me, but as you said it could be the dye. Try using an eyedropper (or syringe) and put a few drops of olive oil (Not too much!!) in her dry food, I would cut back on the mealies as that was my issue with Reia, maybe put on in her food bowl to entice her to eat her food, but no more. Try this for a day or two and see if that helps her to poop.
Quilling also makes a lot of changes for them, someone on here told me that "It's like going through puberty AND teething ALL OVER your body all at once". What are you feeding her for food?