On kodak all in printers, notably the esp 5, the ink cartridges are depleted even without use. The ink just evaporates because of poor design of the print head and other components. You can go use up a color cartridge in 3 months without ever printing a single color document. The black ink cartridge also just evaporates. Maybe that's why their so called ink monitor shows both cartridges at the same level always regardless of their utilization.
I will never buy another Kodak printer product. I am going to look for a decent price color laser to beat both Kodak and HP at their ink game. One evaporates the other just clogs up.