ICC profiles are a cross-platform file format that can be used on Mac, Windows, Linux, or other platforms without conversion.
If you have problems regarding moving profiles cross-platform, they typically show up as a result of the operating system differences rather than actual color issues.
Macintosh: The most common problem is when the profile does not have the correct Mac "type" and "creator" codes set. These are the invisible codes that files on the Mac use to keep track of what kind of file it is (the actual data contents like TEXT or PICT) and the application that created it. If your profile has a blank white icon - a typical sign - and ColorSync is ignoring it so it will not show up in any menus, it probably needs the codes set.
Follow the link below to the "Make ColorSync Profile" utility. This is a small drag-and-drop utility that you can drop profiles onto and they suddenly get the correct icon. Problem solved. Also - the utility is for Macs only and must be run on a Mac - there is no way to set these codes before you send the profile to a Mac user.
CHROMiX ColorThink will also detect this problem and fix all the profiles on your system at once as well as other such issues. For more on ColorThink, go here
Windows: Typically profiles without an expected 3-letter extension cause the common confusion on Windows. Microsoft originally used the ".icm" extension for profiles but now officially prefers ".icc" (and we could not agree more). Older applications and RIPs might expect only the .icm extension and ignore .icc profiles until you change them to .icm. We recommend naming profiles with .icc and then change to .icm if you have a problem. Grumble at the applciation's developer the next time you talk to them to change to the new method too...
Just for the record there is no difference between an "icm" profile and an "icc" profile; other than the fact that there is no such thing as an "icm" profile really - it's just an icc profile with another extension.
Kodak and a few other companies have also used the ".pf" extension in the past but that use seems to have faded. Again, we recommend .icc to avoid confusion.