When you print a color-managed document, you can specify additional color management options to keep color consistent in the printer output. For example, suppose that your document currently contains a profile tailored for prepress output, but you want to proof the document colors on a desktop printer. In the Print dialog box, you can convert the document’s colors to the color space of the desktop printer; the printer profile will be used instead of the current document profile. If you select the Proof color space and target an RGB printer, InDesign converts color data to RGB values using the selected color profiles.
When printing to a PostScript printer, you also have the option of using PostScript color management. In this instance, InDesign sends the document’s color data in a calibrated version of its original color space, along with the document profile, directly to the PostScript printer and lets the printer convert the document to the printer color space. The printer’s color space is stored at the device as a color rendering dictionary (CRD); this makes device-independent output possible. CRDs are PostScript equivalents of color profiles. The exact results of the color conversion can vary among printers. To use PostScript color management, you must have a printer that uses PostScript Level 2 or higher; it is not necessary to install an ICC profile for the printer on your system.