Possibility
Yes, your grandparents or parents on both sides might not be red heads,the baby might be coloured like one of them.
Yep I'm studing this kind of genetics in my freshman class its called genes the reason this happens is when p1(parent) mate together the too may be both heterozygous and have a dominate and recessive alle since red hair dominate over___*can't think of color less dominate but you catch my drift* it make the recessive alle invisble but when they have a child whose has lets say blonde is because even though percent is low the random gene tranfer in fertilization anthing can happen *which the child is consider the f1 generation*(p.s alle is just fancy for dna f genes somthing like that peace!)