The reason the majority of hair colors are brunettes is because it is a dominant trait. It could be in both the king and queen's family line there was a blonde and they both ended up being carriers of those traits (red hair is an even better example, as it is the rarest.) Eye color is trickier, not to mention the baby has golden eyes. But true to form, brown eyes are the most dominant so once again, both parents could have been carriers.
But yes, my first thought was just like everyone else's. I think since the queen had similar traits to the king, they might have come to an agreement to have the concubine knock up the queen to have the best chance of the baby looking like the couple.
And I don't even mind the concubine visiting the prince, as both his parents actually don't seem like they give a sh*t. My problem will be if the baby is taken away from the queens quarters because of one little word from the concubine.
That concubine is a witch or rather a bitch. He used black magic to make everyone fall in love with him and the king had to be his ex-lover (in his other life. ?) And the used that black magic to make the son look like him cause the side effect of that black magic was that his body was being rotton.. And when his body died he could be the son and be with the king forever.. So the king and the son ends up together.. Is what I read.. Sorry bad grammar..
So...if the dad has black hair and the mom does too.. or like them having a darker hair color, how is the baby blonde?
Or am I missing something..? But the baby is cute though. :)