Andy encounters the strange island, where every creature has either green, purple or blue hair. He's told by a reliable souce that those with green hair always tell the truth, those with purple hair always lie, and those with blue hair make statements that are alternately true and false (though the order of which statements are true and which are false is unknown). One day, Andy meets three of the islanders, but each is wearing a very big hat which completely covers his hair. Andy asks each of the three the color of their hair and the three respond as follows:
A. " C still counts using his fingers and toes. B needs to have his own abacus. I do not have purple hair"
B. "I do not need to have my own abacus. I have blue hair"
C. "I disagree with A's first statement. I have green hair."
Assuming that each of the three has a different color hair, determine the hair color of each A, B, and C. Explain your answer fully.