Why are the Boxes all painted different?

All the painted boxes are Queen Mating Nucs I took them to some local schools for the kids to paint. The artwork is amazing and sure to make me smile when I see them for years to come but the purpose is for them to be unique. When the freshly hatched Queen leaves the Nuc to be mated she begins flying upward higher and higher in circles. Drones (Male Bees) in the area will sense her pheromones and begin following her upward. A Queen will mate with the multiple drones that are able to fly the highest and therefor are the strongest/healthiest. When she returns, she needs to be able to find her exact hive or risk entering the wrong hive and being killed as an intruder.