How imported images are integrated into a document’s color space depends on whether or not the image has an embedded profile:
A safe CMYK workflow ensures that CMYK color numbers are preserved all the way to the final output device, as opposed to being converted by your color management system. This workflow is beneficial if you want to incrementally adopt color management practices. For example, you can use CMYK profiles to soft-proof and hard-proof documents without the possibility of unintended color conversions occurring during final output.
Illustrator and InDesign support a safe CMYK workflow by default. As a result, when you open or import a CMYK image with an embedded profile, the application ignores the profile and preserves the raw color numbers. If you want your application to adjust color numbers based on an embedded profile, change the CMYK color policy to Preserve Embedded Profiles in the Color Settings dialog box. You can easily restore the safe CMYK workflow by changing the CMYK color policy back to Preserve Numbers (Ignore Linked Profiles).
You can override safe CMYK settings when you print a document or save it to Adobe PDF. However, doing so may cause colors to be reseparated. For example, pure CMYK black objects may be reseparated as rich black. For more information on color management options for printing and saving PDFs, search in Help.
Use the following general guidelines to prepare graphics for being color-managed in Adobe applications:
InDesign allows you to view, override, or disable profiles for imported bitmap images. This may be necessary when you are importing an image containing no profile or an incorrectly embedded profile. For example, if the scanner manufacturer’s default profile was embedded but you have since generated a custom profile, you can assign the newer profile.
You can also view or change profiles for objects in Acrobat.