Ursa
Ding! Ding! Winnah!!
explanation of clues:
You can see me in the night sky, but I'm no Greek.
I was never taught pointing is rude.
In fact, I point at myself all the time.
I am guilty of double dipping
I come in many different colors; brown, silver tipped, black and its polar opposite.
I can guide you north.
Minor me gets used in a Major way.Ursa is Latin for Bear, the two Ursa constellations are Ursa Major and Ursa Minor.
If you draw a line between the two stars in Ursa Major that make up the edge of the "dipper", they point at Ursa Minor.
Ursa Major and Minor are also called the Big and Little Dippers, thus double dipping.
Brown Bear, Silver Tipped Bear (Grizzly), Black Bear, Polar Bear.
Polaris, known as the North Star, is located in the constellation Ursa Minor.
Ursa Minor is used in navigation, you can always find North due to Polaris in the constellation.