Different lights make me strange

Question: Different lights make me strange,
for each one my size will change.

What am I?

Question: Look at my face, I am somebody. look at my back, i am nobody. What am I?

Question: I have 6 faces and 21 eyes, but can't see a thing. What am I?

Question: What tastes better than it smells?

Question: Resurrected, they descend by the millions. Sometimes, to nourish and give life. Other times, to take lives or destroy. They have been known to fill entire valleys and block roads only to disappear before executing their long journey back to the top. What are they?

Question: What goes in the water black and comes out red?