2.5.7 Windows: CMYK colors are unnecessarily shifted between documents with different color profiles

[4dimage]

I regularly create newspaper advertisements and printed materials that are produced by online printing services.

Each provider has its own technical specifications regarding the document color profile to be used. Typical examples include ISO Coated v2 300% (ECI) for regular printed materials, and ISOnewspaper26v4 or WAN-IFRAnewspaper26v5 for newspapers.

I often have to make minor adjustments to a specific ad design for different newspapers. This often results in additional work, as every time I change the document color profile, all color areas (vector graphics and fonts) are unnecessarily converted to the new color profile. Then I have to reassign all the colors manually. What a waste of time.

For example, even a simple rectangle of CMYK 0,0,100,0 is shifted to CMYK 2,0,100,0 in the target document.

For newspapers in particular, a color profile with a low overall ink coverage (e.g., 240% or 280%) must be selected. However, that doesn't mean every color needs to be converted! That might only happen if the total ink coverage is actually exceeded. But that's certainly not the case with 0, 0, 100, 0.

The error occurs when the document color profiles differ between the source and target documents, regardless of the actual need to limit the total ink coverage.

Of course, the screen display of the colors changes! But the underlying CMYK color values should remain unchanged.

 

Here are two source graphics, each with its document color profile, and two target documents in which the graphics are placed.

test-source-isocoatedv2-300.afpub

test-source-isonewspaper26v4.afpub

test-target-isocoatedv2-300.afpub

test-target-isonewspaper26v4.afpub

 

1) The unnecessary color shift occurs even when simply copying via the clipboard between documents with different color profiles. Neither the red nor the yellow have an excessive total ink coverage. Nevertheless, both colors are unintentionally changed when pasting. It is possible to manually reset the CMYK color values in the new target document to their original values using the color palette. Therefore, the current document color profile does not necessarily prevent certain color values.

 

2) The same applies when placing. As soon as the color profiles differ between the source and target, the colors are unnecessarily shifted.

 

I specifically conducted a test with Illustrator and InDesign, copying and placing graphics between documents with different document color profiles. In these cases, the pure CMYK color values are retained in the target document, even if the screen display naturally differs. So, it doesn't seem to be a standard procedure to always recalculate colors.

 

3) In the Publisher document properties, on the "Color" tab, there are the options "Assign" and "Convert." Unfortunately, it's not possible to permanently enable the "Assign" option. Every time the dialog is reopened, the behavior reverts to "Convert." This could be the reason for the color shifts.

 

There must be a mode in which the pure color values of inserted vector graphics remain untouched. Especially if the target profile actually allows the color values to be manually reassigned.

[4dimage]

I've managed to switch a document from one document color profile to another without changing the CMYK values. Only the screen display changes.

The point is that when switching, the "Assign" option seems to work, at least for this one action. In this example, I'm changing the document color profile from ISO Coated v2 300% to ISOnewspaper26v4.

a) First, with the "Convert" option. Then the CMYK color values are shifted.

b) Then, with the "Assign" option. The CMYK values are then retained, although the display on the screen still changes.

It's not possible to permanently set the "Assign" option in the document properties. So, I think the procedure in the dialog described above was exactly how the developers intended it. Similar to the scaling behavior when the document or layout page size is scaled to a fixed size.

Not really satisfactory, since you can't even quickly copy a modified graphic from one document to another via the clipboard. You'd have to first set the source and target documents to the same color profile, and then, after pasting the image into the target document, set it back to the desired color profile. And don't forget to activate the "Assign" option in the dialog every time!

There's also the problem that, even with linked vector graphics, the color values in the target document are still shifted according to the active color profile.

 

Why is this so important?

1) As described, I frequently have a situation where a specific ad layout is published with slight adjustments in different newspapers. Each newspaper may require a different color profile in its technical specifications.

So, if last-minute additions need to be made during the design process, it's difficult to create them in one layout variant and simply duplicate the new element in all other formats. Quick copy and paste doesn't work between the different color profiles, as described. Therefore, the colors have to be manually reset each time after pasting.

 

2) For example, I have a grid of products with special prices for sales promotions. It's inevitable that individual prices can change at the last minute. To avoid errors after price changes, there's a designer layout file in which the individual items are graphically managed as square insets on named artboards. I then place the Designer artboards as links in the target document in the respective Publisher ad layouts for the various newspapers. If an article price changes, I make the change once centrally in the Designer file. I then open the affected Publisher layout files and export them again to PDF/X-3 for distribution to the newspapers.

e.g.

 

So far, so good. However, since the central Designer file also only has a specific document color profile, the colors of the linked article artboards in layouts with a different color profile are shifted as described.

So I usually have to maintain at least two or three Designer article files in order to be able to maintain the appropriate target profile for the most common newspapers. At some point, the advantage of centrally maintaining the price data is lost, because changes have to be made synchronously in two or three Designer documents.

 

Ideally, there would actually be only one central Designer article file, and the respective Publisher ad layouts would link to it without any changes. This exact process is possible in Illustrator and InDesign.

 

Does anyone have any other ideas for a practical solution in Affinity? Aside from some crazy data merge solution

[stokerg]

Hi @4dimage,

As taken from the Help File

• When applying a different colour profile, Assign adopts the new profile but leaves the values of the colours/pixels as is. Convert converts each colour from the old profile to the new one—colour/pixel values may change as a result.'

So this is working as expected and isn't a bug.  It's more Feedback, so i'll get this moved over to Feedback and Suggestions

On 3/15/2025 at 5:08 PM, 4dimage said:

Does anyone have any other ideas for a practical solution in Affinity? Aside from some crazy data merge solution

Due to the different colour profiles in use between the documents, i can't see another way to do this, other than have 2 sets of files, 1 afdesign file and 1 afpub file each set to the needed colour profile.