Why use ICC v4 profiles?ICC recommends the use of profiles made according to the v4 specification in place of the older v2 specification, as it provides better support for consistent results in open, vendor-neutral, cross-platform color management systems.
Benefits that users will see with v4 are:
V4 raison d'etre to enable intelligent CMMs and improve results for non-linear color spaces contains the V2 - V4 technical changes and benefits list.
While ICC recommends the use of v4 profiles wherever possible, it recognizes that v2 profiles continue to be used in some workflows and can give good results. Some recommendations on making v2 profiles are provided for developers.
In PDF/X workflows, Ghent Work Group Process Control subcommittee previously recommended restricting ICC profiles in PDF/X to those made to the older v2 specification. The group is currently testing the use of v4 profiles in real world PDF/X-4 workflows. See a summary of progress and details of how to participate in the GWG tests.