You did? I think the description in the book says he had brown hair... Here's proof:
Originally, Eragon was human of average height, intense brown eyes, dark thick eyebrows and brown hair. Eragon was described sometimes as smallish or more lithe than average. Roran described Eragon as having a slight build in Eldest. He attended the Blood-Oath Celebration in Ellesméra, where he was transfigured into an Elf/Human hybrid by the dragons' magic. His face became more angular, pale, and smooth. His eyes became slanted and his ears became pointed. His speed, strength, sight, touch, smell, hearing, and taste were all augmented to Elf-like sensitivity. He did retain some human qualities, including thicker cheek bones and the need to shave. Most importantly, he was completely healed of his accursed scar on his back.
After punching a soldier in a skirmish and dislocating his fingers, Eragon used magic to grow thick calluses on his knuckes, similar to the Dwarves' Ascûdgamln. This enabled him to punch hard objects with little or no consequence to his hands."
I copied this from http://inheritance.wikia.com/wiki/Erago ... appearance