I have a custom ICC profile for my printer or specific output. I need to install it on macOS to be used in Capture One later on. How can I do that?
Unzip the package with the ICC profile
Typically, ICC profiles are usually available in zipped packages so that the file is compressed. Unzip the package by double-clicking on it prior to installing as neither the operating system nor Capture One can parse a zipped ICC profile.
Copy the ICC Profile file
Click on the profile file to highlight it, then select Edit -> Copy to copy it.
Paste the file to the Profiles directory on macOS
Open Finder, then select Go > Go To Folder.
In the resulting dialog, type "~/Library/ColorSync/Profiles" (without quotes).
Select Edit > Paste Item to insert the previously copied file to the Profiles folder
If you are asked to enter your user name and password, simply enter it and proceed.
Restart Capture One
As Capture One parses these folders for usable profiles when launched, it is necessary to re-launch Capture One so that the new profile is visible to the application and the changes take effect. The new profile can now be used as a Proof Profile which can be accessed via View -> Proof Profile.
The same goes for the destination profile for the processed file (which is set under the Process Recipe's Basic tab) or as a printer profile (in the Print dialog's Color Profile option).
If the profile does not appear on the list, make sure that the file is present in the Profiles folder.