Remove the function of the old printers that you could put any colour ink in it and have it print in that colour, and make it so that you can only use ink sacks for normal printers. Advanced printers would have the user put in magenta dye, cactus green, cyan dye and ink sacks as well as paper, and you would be able to print more than one colour onto a page. You would be able to print paintings made with paint, code WITH the syntax highlighting, and things like:
printer.setTextColour(colours.COLOUR)
printer.setPageColour(colours.COLOUR) *
^ them could be added.*Note, may be hard to implement
An idea some people posted below were, rather than putting in all the dyes, you could use ink cartridges. That is a better idea than I had thought of! They could be made like:
and that would make an Empty Ink Cartridge. Combine that with magenta, cactus green, cyan and ink sacks and you would get a Filled Ink Cartridge. This would be used in an advanced printer instead of putting in all inks. As you use it, it gets a durability bar like tools would. After 30 prints (or 50 if you only use black and white) it will turn back into an Empty Ink Cartridge.
Thank you for taking your time to read,
[indent=6]Shnup ^_^/>/>[/indent]
TL;DR: Advanced printers print in colours when used with colour dye or ink cartridges