ICC profiles are a crucial building block for color management and play an important role for describing PDF/X and PDF/A output intents. The common sRGB ICC profile is built into PDFlib, and can be used without any additional configuration.
ICC profiles for other common printing conditions, especially CMYK, are available for download in the ICC packages on this page. They can be used with various PDFlib features, including image tagging and specifying output intents for PDF/X and PDF/A.
After unpacking the profiles they must be configured in PDFlib according to the documentation (e.g. using the SearchPath resource category).