Oh yes. His clothes are red. In the original legend the Pied Piper weares first very colorfull clothes when he arrived at Hamelin and helped the town to get rid off their rats but when he came to get the children he weared red clothes. And the reason why he is wearing red clothes is because the color red represents the devil himself.
Very interesting! Here are some Pied Piper images
And seeing these children wearing little devil masks, dancing around a fire and led by an powerful representation of the devil really reminds me of Walpurgis Night