I thought of Léa Seydoux in Blue is the Warmest Colour (a likely Oscar contender for Best Foreign-Language Film) but maybe that's just me - and that's certainly not YA or the cinematic equivalent. I haven't read Daughter of Smoke and Bone either and I'd question that the character there is as iconic as the OP suggests. If the character was a teenage boy with glasses and a lightning-shaped scar, then that might be different.
I haven't seen the movie yet but want to. I haven't found many theaters here in NYC showing it since it's not a "mainstream" film here. I completely forgot it, so thank you for reminding me.
And I agree, I don't think the character from the book OP mentioned is iconic enough to require a change the MC to have a different hair color. Harry Potter is a perfect example of a character with iconic character descriptions. I doubt OP would be in any trouble having a FMC with blue hair.