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?

[![At the
tip](https://i.stack.imgur.com/a1swG.jpg)](https://i.stack.imgur.com/a1swG.jpg)

I didn't think it was Busō-shoku no Haki, because that's black:

[![enter image description
here](https://i.stack.imgur.com/XWOXf.gif)](https://i.stack.imgur.com/XWOXf.gif)




it's Busō-shoku no Haki (should be black but Toei since Punk Hazzard have
colored the CoA with that color).




it's Busō-shoku no Haki (should be black but Toei since Punk Hazzard have
colored the CoA with that color).

