Tonight, as I thought of Polaris and how often other green-haired characters have been mistaken for her, I started thinking: how many cases are out there of X-Men characters sharing the same unusual hair color?
My knowledge is very limited since I'm not a hardcore X-Men fan, so I figured it would make the most sense to ask here. This is what I know.
Green: Polaris, Agent Brand, Vertigo, Shade, Doc Samson, Viper, Trevor Fitzroy, Gideon
Pink: Pixie, Blink, Marrow, Quentin Quire, Cerise, Ruckus
Purple: Psylocke, Revanche, Catseye, Snoop Dogg (CBR user)
Silver/White: Storm, Spiral, Quicksilver, Magneto, Warbird, Maxime, Manon, Strong Guy, Hindsight, Cable, Maggott (when powered up)
White streak (not all white): Rogue, Eva Bell, Nate Grey, Domino, Sunspot
Blue: Surge, Mach-Two, Whitney (Mystique Black), Colubrina (Amazing Nightcrawler)
Multicolor: Ariel (pink/white/blonde), Riptide (lilac/white), Oracle (blue/white)
What others are out there that I missed?
EDIT: I'm going to add characters other people pointed out in replies, and use underline to show they were pointed out by others later.