It probably depends on your printers functions and drivers....
In version 11, when you select Print, an option box pops up with several tabs. Under the misc tab, there is a "Proofing Options" box. In that box are some radio buttons. On the left hand side, one of them says "all colors as Grayscale". Since this same dialogue box is present with multiple color printers we have here, i am assuming it is a Corel Draw dialogue box, and not a printer dependant driver dialogue box.
HTH,
Russell