The Boys' Bedroom (more improvements)

Grandma found these wall hangings recently for Aaron and Donovan's bedroom. They came as a set of three - red pickup truck, blue front loader, green cement mixer. She bought one set, and then went back to the store and bought a second set!
We considered several combinations and locations within the bedroom, and in the end decided to arrange them in a line across the full length of the wall. Donovan helped pick out the pattern of red, blue, green, red, blue, green. Three of the vehicles are above Aaron's bed, and the other three are above Donovan's bed and the bookcase. Before nap and bed each day, Donovan says, "That's my green cement mixer, and that's my blue front loader, and that's my red pickup truck. I have three. That's Aaron's green cement mixer, and that's Aaron's blue front loader, and that's Aaron's red pickup truck. He has three."
Now, we just need Aaron...