Prepare cake mix according to bag instructions. Measure out 1 pound batches and make 4 colors using blue, violet, maroon and pink food coloring. Place prepared cake mix into sprayed quarter sheet trays and bake until cake springs back lightly when touched. Let cake cool completely. Use a round cutter the same diameter as the push pop container, punch out circles. Save scraps for cake pops. Lay a cake circle in the bottom of each container then pipe in buttercreme. Repeat until all 3 colors are in the pop with buttercreme in between. Top with a buttercreme swirl and sprinkles.