There is no way to print a color image in grayscale on the Color LaserWriter 12/600 PS or Color LaserWriter 12/660 PS printer if the image is an Encapsulated PostScript (EPS) file, or the application you are printing from generates its own PostScript.
Applications like Adobe Illustrator and Aldus Freehand generate their own PostScript, therefore if any color is used in the document, the application generates calls to PostScript color operators. When the document is sent to the printer, the driver recognizes the data is already PostScript and forwards it to the printer unchanged. Thus, the printer driver is never used to generate the PostScript and driver settings such as Black & White are bypassed. The Color LaserWriter 12/600 PS printer directly executes the PostScript coming into the input stream and since it encounters a color operator, prints the document in color.
This article was published in the "Information Alley": Volume II, Issue 19, Page 12