Ok read this a long time ago and have forgotten the title/ author. Set in an ice world, people skate around, there are tribes of outcasts called 'cutters' who can transform people's appearance. The main character has black hair, but with red hairs that come through as he gets older. His father was an unknown evil king or something with the same hair, his Mum would pluck the boys red hairs out so he wouldn't guess who his real father was. Thanks all!
Could it be Neverness by David Zindell?
It's ages since I read the book and I remember little about it, but there are artisans called Cutters who can change your appearance. The protagonist Mallory Ringess goes to a Cutter to have his appearance changed, though I confess I don't recall exactly why.
Mallory Ringess is the son of Soli and he does have red hairs that his mother plucks to conceal his parentage. I managed to find that scene in the book:
I remembered my mother plucking the supposedly ‘grey’ hairs from my head in the Devaki’s cave when she groomed me for lice, and the riddle of my heritage was no longer a riddle. She had plucked red hairs from my head, not grey. Red hairs, the hairs of the Soli lineage that sometimes do not appear until early manhood.