Answer:
I am seen in the water. If seen in the sky I am in the rainbow a jay's feather and lapis lazuli.
I direct you from outer space.
I've been argued on my color. Without me you'll die. So many attempts on your life use me so make sure you have many of my White friends.
I am the noise Santa's reindeers make
I start new then become old. Start clean but be one dirty. I usually start big then become little.
What do you purposefully put lots of in and on your body, but run away from when you encounter it outside?