[X] - Well, the Elders tell you to 'do something about it', so that's what you'll do: You'll make sure Naruto is professional about his pranking.
-[X] - First off, what's up with him getting caught all the time despite being sneaky enough to do all this crud? You'll introduce him to the concept of minions, scapegoats and alibis, because it's awesome to have people stuck because they can't prove you did something!
-[X] - Second off, where's his variety? Paint, paint paint paint - it's getting boring, and he even sticks to the same general extra garish colors. Diversity's key if you want to keep things fresh - rigging prank traps in people's houses like projectile egg cartons in the fridge, whatever really so long as it's new.
-[X] - Third off, he should really be less trusting and open to someone just randomly giving him help, as they can learn more than enough to get him back. Demonstrate this, by finishing your lesson by framing him for a prank on the Akimichi clan and making sure he knows it.
-[X] ...Along the way, find out the names of what paints and dies he used on you. You plan to keep your room the same color, and you imagine being able to easily restore it should ill mannered elders see fit to change it would help. Also you don't really mind the blond look.