Where does the ink go?

[gavroche]

I have a Lexmark printer and it is used 99% for black and white work, yet the levels of the colour cartridges goes down quickly for the very little times I use them. When they are nearly empty, I need to replace them otherwise the printer won't work, even for black only work. So where do the colour inks go?
Got a bargain from Currys today: 6 colour cartridges and 4 black ones for £5.96 in total!! Just one colour Staples is £13.49. Happy chap.

 

[raleighnut]

The printer clears all 'nozzles' every time you switch it on.