Hi
I have a Canon i550x printer which until a few weeks ago printed perfectly. Now when I print out anything the colours are very pale. The black is ok. I have run the clean nozzles and  deep clean set-ups. Checked all sorts of adjustments. Installed new inks but whatever I do I cannot get the colours to print correctly. Tried different paper settings, but all to no avail. Is there a life span to these machines as I cannot see any mention of this fault in the Help Menu or Print Trouble Shooter.So you have changed the color cartridges?
What about the black ink cartridges? How do you know they're ok?

In my experience, bad color quality was the result of low blank ink, so you might want to LOOK into that.

Also, can you make sure you're not printing Drafts. (Usually in Print setup)If I'm not mistaken, sometimes when the black is low, like Carbon said, the printer will draw from and combine colors to make black.

Alan <><  You pop up at the strangest times, Alan. My wife just left for work and my office is in the garage.  Before I have to climb the stairs I usually take a whack at the forums. 

Alan <><  Heh, all right.There is a method to the madness 

Alan <><  Have checked. The black is almost half full.
I have just printed a test sheet in 3 colours without black of the LETTER A, in 72 point, Bold 'Arial Black' and they have come out 'faded'. There appears to be horrizontal missed lines across the whole page of letters especially the Blue. As I said before I gave the nozzles both a Clean and Deep Clean.How exactly did you clean them?

Can you make sure you're not printing drafts.

If you have any spare black ink cartridges, I would try them out and see if there is any difference. Quote

Installed new inks