"Well, Remus informed me about his plans to sneak into the girls dorms using our new -- talents, skills, you know -- since you didn't relay such important information to me you prat" Sirius said, poking James in the shoulder before continuing. "And it got me thinking. Why should we prank our own house when we've got three others to do it to which naturally led me to believe the worst and greasy ought to be the victims of our genius plans and so I feel as the Marauders we need to act using such important information. Which is to say we need to put a potion in the Slytherin's shampoo to turn their hair our house colors for a week, preferably before, during, and after a Quidditch match."