Harry saw the gold Gryffindor lion, emblazoned on scarlet; the black badger of Hufflepuff, set against yellow, and the bronze eagle of Ravenclaw, on blue. The silver and green of Slytherin alone were absent.
This is one of my big disappointments with this series. I always wished there would have been more inclusion of the Slytherins in the rebellion. As it is it's more like the Slytherins that are fighting Voldemort are the exceptions - reinforcing the idea that Slytherins are "bad" or "evil". *sigh*
I always wished that everyone would have taken the Sorting Hat's advice, about combining together to fight, more to heart.