Casting Harry and the fact black hair with green eyes is a rare combination

I don’t remember the last time I met a white person with this striking natural combination of hair and eyes in real life. It's difficult to find even amongst actors (Jennifer Connelly is one). The combination exists, but it’s rare... which is part of what makes Harry visually interesting but also difficult to cast accurately. Dark brown hair with blue eyes is more common. I think it likely that we’ll once again get a brunette, blue eyed Harry. If we do get a green eyed Harry, he will probably also be a brunette and not have true black hair.

Contacts aren’t a good long-term solution for changing an actor’s eye colour. Not only can they be irritating to wear (especially for a child), but coloured ones can also affect how expressive eyes are. The human pupil changes size autonomously in response to light and other triggers. Coloured contacts don’t allow changes in pupil size to show through, giving eyes a subtly uncanny effect. Personally, I always notice when an actor is wearing them; they never look natural.

They could cast someone with green eyes/light hair and then dye his hair black, but it’s a lot to ask a child to dye their hair for the next ten years. There's also the problem that not everyone suits dark brown or black hair. They risk casting someone who looks overpowered by or weird with dark hair.

So long as they actually match Harry’s eyes with Lily’s this time, I’m not too fussed if Harry has blue eyes. I do wish we could get a black haired/green eyed Harry, though, but it just seems unlikely. Even if they do find such a boy or even two, there's no guarantee they'd be the ones with the acting prowess or chemistry with the other kids. I know it's important to this sub that actors look like their characters but in Harry's case, due to his appearance being statistically rare, I think some allowance will be necessary.