What is the purple stuff on Doflamingo's strings? In the latest episode, we see a pure purple color at the tips of the string attack. I've never seen this before. What is it?



I didn't think it was Busō-shoku no Haki, because that's black:
it's Busō-shoku no Haki (should be black but Toei since Punk Hazzard have colored the CoA with that color).