The Best Hisoka's Hair Color References. Web well, consider that in the 1999 one he goes from light blue/cyan to orange. Blue (1999), yellow (2011) body measurement:
Hisoka's 2011 anime adaptation design 2. During the 13th hunter chairman election arc. Web in some scenes his hair seems purple on some parts (either in the back, the roots, the ends or randomly on his head (seems like a patchy hairdye)) but on the other hand it sometimes looks like these purple parts are just shadows.
