After much reading.. I summarise this....
Black Pastel X Pastel = Black Pewter
Black Pewter X Pastel = Silver Streak
Cinnamon X Pastel = Pewter
Pewter X Pastel = Sterling
Black Pewter X Pewter = Silver Bullet.
Black Pastel X Black Pastel = Super Black Pastel
Cinnamon X Cinnamon = Super Cinnamon
I wonder... Silver Streak X Sterling..