Don,t know about purple ones but I can highly reccomend dogmatic for their webbing non slip leads, I walk GSDs with them and they don,t bother my hands. Its my shoulders that achealong with my hips and knees known in the breed as German Sheperditis.LOL.
Try Canine Concepts (sorry, can't do links). They do them in different lengths starting at £3.49 for 6' and going up to about £8.00 for 30'. I use them and they are excellent.
I use these cotton dog leads. They are really strong & comfortable on the hands. They also wash well in the washing machine. My dog walker remarked on how good they are and wanted to get some for her 3 GSDs.