Hi! So my colour setting is set to CMYK in InDesign, but when I export the document to PDF (print quality) the colours still turns dull. Is there a way to preview the "true" CMYK colours when editing in InDesign? So I can avoid unpleasant suprises like this.
First off, check your Color Management settings in all your CC apps to make sure they weren't reset to something other than what you expect. There was bug a couple of point versions back of PS and Illustrator that reset these settings: supposedly fixed now, but that's not to say your settings weren't changed before and you hadn't yet noticed. If you use Bridge to sync all your settings, check there first.
Second, if your intention is going to print and are designing with out of gamut RGB colours/Pantones, then yes, these "bright" colors will convert duller.
Third: what are your export settings when creating your PDFs... particularly the settings for Output > Color Conversion?
My "Color Conversion" is set to "Convert to Destination (Preserve Numbers)", and my "Destination" is set to the standard "Document-CMYK-Coated FOGRA39 (ISO 12647-2:2004)".
As far as "is there a way..." , YES there is.
You want to turn on "Proof Colors" under the "View" menu to show what differences will occur based on your Color Settings (CMS).
In my attached sample, I'm using two Pantones I know are out of gamut for CMYK printing: PMS165 (orange) and Pantone Green. On the left is how they look on my screen in with the "Proof Colors" turned off... quite vibrant. For this sample file, I have set my CMS CMYK output to "US Sheetfed Coated". So now, with "Proof Colors" turned on, you can see the change in values on the right, as this is the closest CMYK match.
You can toggle this on and off as desired so you can preview any of your output. Worth using!
Are you viewing the PDF in Acrobat or some other PDF viewer?
If you export using one of the PDF/X presets, Acrobat will use the PDF/X’s Output Intent profile for the preview (the Document CMYK profile in your case) and you should get a match to the InDesign page with Overprint Preview turned on. Other PDF viewers aren’t necessarily color managed and may not use the CMYK output intent profile, which affects the preview.
Also make sure you are not experiencing the color management bug that happened with some recent updates—your Color Settings should not be Emulate InDesign 2.0 CMS Off.
I was using the standard PDF viewer that comes with a Mac. I downloaded Acrobat to view the PDF there instead, and the colours matched with InDesign's. Glad we solved that mystery. I did not know the PDF viewer could affect the colours so much! What can I expect when I send the document to printing? Should I be prepared for something like shown in the PDF viewer or in Acrobat?
Apple’s Preview app accurately color manages objects, but only if they include a color profile—an embedded CMYK color profile handles the CMYK object’s soft proof preview.
From InDesign you can export to a preset that converts all color to CMYK, but does not include any profiles—the default [Press Quality] preset does that. With the Adobe apps, objects with no color profiles fall back to the document’s assigned profile (Edit>Assign Profiles), and if the document has no profile the fall back is to the Color Settings’ Working space. Preview doesn’t have an equivalent of Adobe’s Color Settings, so it can’t accurately preview the CMYK color with no embedded profile.
The PDF/X presets, which are designed for press output, also include an Output Intent profile. In Acrobat the Output Intent Profile handles the preview of CMYK objects which have no profile—Apple’s Preview doesn’t respond to Output Intent Profiles. If the output is to the intent profile—Fogra39 in your case—the document CMYK values are output unchanged and the Fogra39 preview is the best soft proof.