Double the fun
You are on an island where there are two kinds of people: those who always tell the truth, and those who always lie. Half of the islanders have brown hair and the other half have blond(e) hair. What hair color you have has no relation to whether you are a truth teller or a liar.
One scorching day, you duck inside a cool alcove to see two natives deep in the shadows. You can't see their hair color.
"Hey!" you call out. "Are you liars, and what color is your hair?"
Native A says: "Both of us have brown hair."
Native B says: "Both of us are liars."
What are they?