Pixma IP4200- not printing color

Worn print head. And for what they charge for a stinking print head you can get a new printer for less with a warranty to boot!

It's going to cost you ink but your may get it working again.
- Remove all ink cartridges - Remove the printhead itself - Carefully (avoid splashes!) hold the printhead under running warm water until the water runs fairly clear - In a bowl large enough for the printhead, put about 1-1 1/2" (25-40mm) of household plain or 'sudsy' ammonia - Set the printhead in the ammonia and ignore overnight - Repeat the water cleaning - Shake out as much of the water and you can, then allow it to dry for at least 24 hours - Reinstall printhead in printer I have better results starting with fresh ink cartridges but have had to use a removed one now and then.
This is one of the printers that does not object to frequent use but will clog if allowed to sit too long between operations. If your memory is better than mine, do one of the print tests every couple of days.

Either the ink you are using is not going to give the color you want, or you have print heads that are blocked.

Maintenance your cartridge with head clean or deep clean. If you don't get full colour, then change the colour cartridge.

I think the problm lies between the ink tank and the printhead. When this passage runs dry, sometimes it takes time for the ink to fill this passage again. Try printing again after a day or two.

Canon printers do not like the refilled ink cartridges. After having ruined a few printers trying to "save" money. I went back to genuine Canon ink and have never had a problem since.

In both cases be sure using correct ink. Use of generic ink can lead to leakage of catrridge seats do to crossion from inferrior ink quality (per Cannon). Be sure ink in proper locations - see manual. Run the maintenance proceedures: cleaning then print nozzle pattern. If all colors are not proper after two or three cleanings, perform deep cleaning. Print nozzle pattern after each cleaning. This should clear up problem. If not, print head may need replacement.

remove print head assembly. clean off.
print head not on cartridge. 

Look for ink clogged on the printer head. Run cleaning or deep cleaning after installing the new cartridge before printing. Take nozzle check print.

Have you tried Canons FAQ? They suggest checking the grayscale box, which apparently only works with certain kinds of printing (duplexing and borderless will still use colors). I don't understand how colored inks are used to create black, but that's what they claim. Anyway, here's the link: http://www.usa.canon.com/consumer/controller?act=ModelInfoAct&tabact=SupportDetailTabAct&fcategoryid=257&modelid=11641