How do i figure out which ink is getting low on my printer, when the ink level indicator doesnt work? -

the low ink light is blink on my printer, but the ink level indicator isn t working on my computer. how do i tell which one it is, without just printing until one runs out!?

try tapping the cartridge against something if the ink doesnt get darker then its time to get it refilled or buy a new one

when the print starts to fade