Colour difference dilemma

As Rob has mentioned, all documents should have embedded profiles, this allows applications to "know" the originators intent for colour and tone..

Bob,

Although I believe that It's right that ICC profiles should be embedded I don't believe that they must all match, in my understanding, the beauty of device independent colourmanagement is that images, or any "documents" with embedded ICC profiles are interpreted correctly within the colourmanagement process.

It's not bad practice, though, to make sure ICC profiles match during the production process - as long as the conversion from one colourspace to another is handled with care.

It's worth pointing out that [although offered] there is no "Perceptual" rendering when converting between working spaces (unlike when converting from working space to a CMYK ICC). Some users rely heavily on Perceptual rendering's (much misunderstood, but that’s for another post) characteristics - not realising they are not available in this scenario.

Example:

If you have a Pro Photo RGB file to place it may be better strategy to place it 'as is' and allow the later CMYK conversion to deal with the compression rather than to convert in advance, to, say, Adobe RGB. That conversion can be damaging unless some care is taken to avoid the almost inevitable clipping in that conversion.

All conversions working space to working space are relative colorimetric with the inevitable clipping if the original had colours close to gamut boundary - that’s why those conversions need a lot of care. Maybe some manual de-saturation so that detail in edge of gamut areas is not destroyed.

Or even approach this by using Joseph Holmes special "nested" workingspaces https://www.josephholmes.com/profiles/rgb-working-spaces but again that’s another subject

I hope this helps

if so, please do mark my reply as "helpful"

thanks

neil barstow, colourmanagement

What preset did you use to make the PDF?

The common PDF/X-4 and PDF/X-1a press presets export CMYK objects that use the document’s CMYK profile as DeviceCMYK—the CMYK objects have no profile assigned in the exported PDF. If you view in AcrobatPro, or Acrobat Reader, the PDF/X Output Intent profile (which is the same as the original document's CMYK profile) is used to color manage the soft proof display of DeviceCMYK objects.

Preview does color manage, but does not read Output Intent profiles, so DeviceCMYK objects will not necessarily soft proof correctly in the Preview app even though the output numbers are correct.

You mean the dark blue R1 G1 B5 in the left side

i don't see how any printed media could reproduce 1/1/5 as anything other than black to the naked eye

even the right side RGB 0/1/14

but whatever color you are trying troubleshoot, a solid fill may simplify

but to the visual mismatch on the screen

you must get your source profile and color settings in order

and nothing in color-managed Adobe apps will match until you:

1. use (apply) the same correct source profile
2. ensure your color settings are not changing your source document

at that point Adobe apps should use the embedded profile and make consistent color translations/conversions/corrections to the monitor profile

lastly, if you are using pantone spot colors in Adobe, i would expect room for error on the monitor between apps - it seems more of an art than a science to most users and not too many people know how Preview.app deals with pantone and spot colors in PDF, but if it's correct (what you want) that's a huge clue...

What you're showing here is missing color management. If you need colors to be reasonably accurate, you need to have a basic understanding of color management and color profiles.

It's not difficult. You just need to make sure that a) there is a color profile embedded in the file, b) it's an appropriate one for the intended use, and c) the color profile is correctly interpreted by the application.

In Photoshop and Illustrator you go to Color Settings, and under Policies make sure it's set to "Preserve Embedded Profiles". Then everything will be correctly handled.

If you want to see things correctly on screen, you also need a profile for that. A calibrator will make that for you.

Generic RGB/CMYK color codes are completely worthless, made by people who have absolutely no idea what they're doing. Numbers are relative to whatever color space is used! They mean nothing if color spaces aren't specified. RGB isn't a color space, but sRGB, Adobe RGB and ProPhoto RGB are. A set of numbers in one color space yields a completely different color in another - and a certain color has very different numbers in different color spaces.

The default working spaces for Photoshop and Illustrator are sRGB for RGB, and US Web Coated (SWOP) for CMYK. They don't have any particular significance, but there has to be some defaults, and these are it. So people who don't know anything about this, tend to just take these for granted, and "color codes" therefore tend to refer to sRGB and US Web Coated (SWOP).

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The basic principle of color management is very simple. A source color space is converted/remapped into a destination color space. This recalculates the numbers in order to preserve appearance, using icc profiles to do the math. A profile is a description of a color space.

The source is usually the document, so you have a document profile, which is normally embedded in the file. The destination can be your monitor, having a monitor profile, or a printer, using a print profile that describes printer/paper/ink. All color management requires at least two profiles, one converted into the next in the pipeline.