Hi

I do not think that this is an issue with Firefox, but I will try to help.

In the printer settings on your computer, you should see the option to print in black and white. If you select this, it should print out the page without using any colour toner.

Some printers offer black & white. Check your manual.

You could consider injecting a style rule into the page that instructs Firefox to render it in grayscale for printing. This probably isn't a complete solution, but it seems to show everything in grayscale in print preview on the pages I looked at for testing.

To most easily hack pages, you can use a bookmarklet, a script saved as a bookmark for quick use. Here's how to create that:

(1) Select this entire script and right-click > Copy it:

javascript:var s = document.createElement("style"); s.setAttribute("type", "text/css"); var t = '@media print{body, div, p, span, h1, h2, h3, h4, ul, ol, li, table, tbody, thead, tfoot, th, td, pre, code, blockquote, img, strong, em, font, [src], [style] {filter: grayscale(100%) !important;} html{background-color:transparent !important; background-image:none !important;}}'; s.appendChild(document.createTextNode(t)); document.body.appendChild(s); void 0;

(2) Right-click a convenient place on your Bookmarks Toolbar or Bookmarks Menu and choose New Bookmark

(3) Click in the empty box next to Location and paste the script

(4) Assign a relevant name like GrayPrint

(5) Click the Add Bookmark button

To test it out, click the button on any page. Then use the Print Preview feature and the colors should be converted to gray values. Hopefully your printer will see it as a B&W page as a result (but I don't have any way to test that...).

(There are some sites that use a Content Security Policy to forbid external scripts from being applied. On those sites, this button will do nothing.)

{ Ctrl + P } then open Properties for that printer. Then locate the Color / Grayscale toggle in the Print driver software.