Use of Colors in Post-Processing Saras could be undefined
Messages > Run-Time Messages > QuarkXPress Processing >
Because of the problems that QuarkXPress has creating new colors programmatically, it is best to avoid using color changes in post-processing Saras.
The reason why this message is modal and not simply logged is that asking QuarkXPress to create new colors is always dangerous. This gives you the opportunity to abort script execution.
Note that this message only occurs if you choose select CMYK color matching in the Preferences (which is not the recommended setting).