Refilling ink cartridges

I guess, I still haven't gotten the knack of refilling colour ink cartridges. I was careful not to inject too much ink and I also let the cartridge stand for a while before inserting it back into the printer. However, I think I didn't insert the needle deep enough when I was injecting the magenta and cyan into the cartridge. As a result, my printer now prints black, yellow and purple. Sigh...

I found a website where one can download videos of how to refill ink cartridges. Very informative and useful.