Do you have an answer for this child’s question?

An inquisitive 4 year old asked her dad, “"Is everybody's skeleton the same colour, even for people from different countries who have different skins?"
The flabbergasted dad thought, ‘ what a simple solution for a heinous and complicated issue Racism.’
Who invented this color theory? Do those fools who divided the humanity on the basis of color of the skin lack this much of common sense of an innocent child?
What’s your opinion? Do you have an answer?