Two apparently identical PDFs display different colours in Acrobat (2025.001.20693)

[Iain Robinson]

Hi

This is weird. I have two cover PDFs exported from Indesign which when viewed side-by-side show different colours but should be the same. The original cover was produced about a year ago and the new one was produced from the previous ones document and both were output to the same colour management settings. When I examine the background colour in Acrobat or PitStop the values are the same in both files but one is noticeably bluer than the other. It's not an issue with a weird spot on my monitor as if i swap the two files around the difference moves with them. If I view the two files in Acrobat X (or a web browser) the files appear as expected.

Just to demonstrate to myself that I am not imagining it I took a screenshot of the files side by side and pasted into Photoshop - sure enough the values are different so Acrobat is displaying them differently. See screenshot attached - I placed some colour samplers in Photoshop.

Never seen this before - anyone got any ideas why this is happening and how to stop it?

Thanks,

Iain

[Luke Jennings3]

Did you use the same export settings from InDesign? for example, an interactive export will result in an rgb pdf and one of the pdf/X presets could be cmyk. Use the Output Preview tool to determine the actual color in the pdf (Tools> Print Production> Output Preview).

[Iain Robinson]

Yes, absolutely. The output intent and how the images were processed tell me that the same PDF export settings were used. And yes the values in the PDF match according to both Acrobat's Output Preview tool and also selecting the objects with PitStop and examining the fill.

[Iain Robinson]

I have attached the PDFs in question so hopefully someone will confirm whether they are seeing the same thing in their Acrobat. I deleted some images from both to keep them within the file size limit.

[Luke Jennings3 · Accepted solution]

I don't see any difference in the background color from one pdf to the next. The second pdf contains two spot colors (in the Taylor Wimpy logo), try using the InDesign ink manager (under swatches) to convert the spot colors to cmyk when exporting the second pdf, do you see any improvement? 

[Iain Robinson]

Thank you. We should really have converted those spots on output to begin with but I didn't think for a second it would affect the CMYK background. But it did - when I convert those spot to CMYK on output the backgrounds match on the old and new PDF. How weird! What version of Acrobat are you using? Any idea why I saw a difference but you didn't?