What is compatible with this ink cartridge? -

It s Lexmark black ink, number 48. I need a color ink to go with it, what should it be?

#48 (black) is the cartridge that probably came with your printer when you bought it new. The retail one you would buy at the store is #50 (black). The color/tri-color sibling of this cartridge is #19 or #20. I believe #20 is the one you would buy at the store and #19 is the one that comes with a new printer. The cartridges that come with new printers have less ink (they are called short fill ) than the separate ones you buy at the store. They are to get you started. Hope this helps!!