What Am I Riddles

Question: What goes black when you buy it, red when you use it, and goes white when you throw it away?

Question: What speaks with its ear, listens with its mouth, and has 10 digits but no hands?

Question: I can hurt you unbearably and can't be touched. What am I?

Question: A powerful spell, the naive knows it well; one cast at an affair for your most popular gown. No sticks, no stones, a mage sans tomes, a fight, no toil but it still breaks you down.

Question: What has a face and two hands?