Wether or not you find the pranks pulled by Sideswipe, Sunstreaker, Bluestreak, and Barricade while Elita and Optimus are on vacation, Prowl's encouragement of them is funny in it's own way.
The explanation for Bumblebee's colors, specifically his and Ironhide's reaction to a home movie of the incident being pulled up.
The youngsters mentioned above paint bomb one of Ironhide's trainee classes. Bumblebee instantly loves the yellow and black colors he got splashed with and Ironhide realizes quickly Elita-1 is going to kill him for this.
The entire scene before hand. Ironhide is doing a boot camp for new recruits... and baby Bumblebee is toddling after him, playing and crawling over him the entire time.
Ratchet's reaction to the above incidents: socking his elder kid in the eye and knocking him flat on his back until he adequately explains why he's encouraging the shenanigans (which are causing a spate of minor injuries). Said "kid" is a highly trained martial artist.