I'd start by coloring the characters from the back first. I would paint Minnie's dress with a nice shade of red, along with her shoes. For her polka dots, I'd use a white marker. Daisy's dress can be painted green and her shoes purple. Her friend's shirt can be yellow and his shorts blue. For Pluto's collar, I'd use a bright red.
Next, I'd color Mickey's clothes. His red shirt can be shaded with a nice bright red, while his polka dots can be filled with a crisp white. His blue shorts and red shoes can be colored as well. To finish, I'd add some white details to his socks.
On Mickey's left and right are Donald and Goofy. Donald's blue shirt and yellow shoes should contrast nicely with Goofy's white shirt and brown shoes. His pants can be colored black.
This fun-filled scene would look amazing with these colors. It's sure to create an exciting coloring experience for any child!