In reply to Slugain Howff:
I don't think it is racism exactly, because it is an attribute of some members of some races (ie red hair is commoner in Scots/Irish) rather than a defining factor of the race (not all Scots/Irish are ginger).
I think something like comments based around slitty eyes would be racist as that is a defining factor of some races (ie Asian/Oriental), whereas black hair is not (most/all Asian/Oriental have black hair but so do black people, Asian/Indian/Pakistani etc).
I do think it is a form of prejudice but it isn't racism.