I have a lexmark x5470 printer and I want to save with ink.

I have a Lexmark, different model, and it won't print without both cartridges in place and I can't put black cartridges in both holders.

In Printer Preferences you can select black only even when there is color on the page, so that is one savings, and you can select 'draft' or 'economy' printing, which gives a light font and saves on black ink.

And once the color cartridge either dries out or is drained you have to install another color cartridge. I believe that's the question.

In the case where one color has run out and you want to maximize pages (when you don't care what the color is)- you may try to continue to print. Even though the image is somewhat legible, the printer may continue to print other color(s) that have run out. This causes the print head to heat up. In Canon printers this is more of a problem and can ruin the print head (which can be separate from the ink supply). If you choose a font color to try to manage this, consider that most printers will interlace the colors into the printed image, even when you choose a printer's primary color. In the case of a Lexmark, allowing the printer to attempt to print colors that have run out, will damage the print head... BUT it has already partially ran out and the print cartridge (with integrated print head) is disposable. Keep printing but, this will damage the cartridge rendering it unable to be refilled. If you are not concerned, then get every drop out with limited image quality.

If you want to save $, then, at the first moment the image quality degrades due to low ink, remove it ensuring that the silver tip of the cartridge (printhead) does not touch anything. Bring it to your nearest cartridge re-filler store and insist that they use a vacuum filling method (same as the original manufacturers do). Do not let the cartridge sit for long periods after removing from the printer to maximize refilling efforts. Your refiller will usually stand behind their work.