I have a Canon MP210, I have a B&W cartridge loaded and I have just loaded a colour cartridge. Everytime I print a message pops up saying the colour cartridge is empty! I tried printing some photos and they appear faint - there's some colour but not nearly enough.

It's definately a new cartridge because I had to peel off the plastic sticker where the ink is released from. Im confused :huh:

Take it back to where you got it from?
Could well be a dodgy cartridge

take it out and put it back in again, when it asks you if you have changed a cartridge say yes and it will reset itself.

if that doesnt work then take it back for an exchange

put printer through cleaning mode
so it cleans nossles etc