After Breakfast Activities!
Notice how the darker fawn pups (left) and lighter fawn pups (right) tend to group and play together. I've noticed that adjacent birth-order pups tend to sleep together during early puppyhood.
The two lighter fawn males were born first. The dark female was third and the darker male was last. The female has the high white socks. The darker male has lower white socks. The two lighter males have very little white on their feet/toes.