When Benji's parents come to pick up their son, the left half of his face has far more yellow paint on it than it did when he was arrested hours earlier.
In the first shot at Juvie, Benji's face appears the same as it had 40 minutes earlier in the vacant lot. However, in the second shot, the dirt on his cheeks are now different, and the grease paint--in particular, the blue side--is now darker.
When Friday and Gannon go to Benji Carver's apartment and find that he has overdosed on LSD, Carver is supposed to be dead, but he blinks immediately after Friday leans down to take his pulse.
LSD can be absorbed through the skin. When Gannon pulled the sugar cubes out of Blue Boy's pocket, the drug could have gotten into his system also.