A:Answer Hello, when your tri-color is out of ink it will require you to replace the ink cartridge. The colors traditionally run out at the same time with the single cartridges as well. However, if you tend to use one color primarily, such as cyan, then you would want to get a printer that uses single cartridges for each color. In regards to the Instant Ink program, it does not matter how much ink you actually use as you are paying per page not per amount of ink used so you do not need to worry about replacing the color cartridge if you join the Instant Ink program which saves you 50% of your ink costs. Thank you for being an HP customer.