The coloring page contains a variety of trucks and tractors in a variety of sizes and colors. In the centre the dump truck stands out in its bright blue hue. To bring the design to life I would color the tractors in shades of yellow, or green depending on what I like, and the trucks in light blue, and brown to add contrast and make the blue of the dump truck stand out. I would use darker shades of blue to outline the shape of the dump truck and also to add definition to the other vehicles in the design. All in all, it's a great and fun design that will look amazing once you give it some color!