Remember you are likely to see the colour output with 1 ink missing hence a blue print when a green one is expected will be caused by a faulty yellow ink delivery. Run a print head alignment test to see which colours are missing (cyan, magenta, yellow or black). If some areas of the printout seem ok then try running a head cleaning cycle
Inspect the colour cartridge you suspect and replace if possible
Look at the printer and assess if one of the primary colours is missing Cyan, Yellow, Magenta or Black. Remember that this fault will be the absence of a colour so if you get an image that is more magenta than it should be, the problem is with the cyan or yellow cartridges.
Double check your source image to make sure it is correct and that the printer driver is set correctly, check things like print quality mode and colour seperation mode
It may be that one of the ink cartridges installed has substandard ink quality stability and should be replaced