Getty The Royal Fam is calling BS on a new book that claims Prince Charles wondered out loud if Meghan and Harry 's child might have a dark complexion. Christopher Anderson claims in a new book, "Brothers and Wives: Inside The Private Lives of William, Kate, Harry and Meghan," that on the day Meghan and Harry announced their engagement, Charles wondered out loud to Camilla "what the children will look like?" Anderson says Camilla was caught off guard and responded, "Well, absolutely gorgeous, I'm certain." Charles allegedly wasn't satisfied with the response, and shot back, "I mean, what do you think their children's complexion might be?" A Palace spokesperson told The NY Post, "This is fiction and not worth further comment." Getty It is odd ... how would that convo between Charles and Camilla leak? CBS Anderson apparently does not say in the book that Charles is the Royal Meghan and Harry were referring to in their …