Answer:
Sometimes black, sometimes white, I have veins but no blood
Until I am measured I am not known, Yet how you miss me when I have flown.
I sleep by day, I fly by night. I have no feathers to aid my flight.
Be sure to shout for its answers are weak, but there is no language it cannot speak.
What goes in the water red, and comes out black?
They are many and one, they wave and they drum, Used to cover a state, they go with you everywhere.