Apply black or a spot colour where CMY colours are used
I have created a file in Indesign and when I run the preflight the following error message appears.
Problem: Content generates cyan, magenta or yellow plate.
Fix: Edit the source file. Apply black or a spot colour where CMY colours are used.
I am sure this has been answered somewhere on this forum, but I am just not understanding it.
Can someone please give it to me in 'dummy' version please.

