Why a CMYK Vector Image Changed Color
March 20th, 2008Our friend Carlie wrote us with a problem that was so perplexing (and the solution so vexing and unpleasant) that I must share it with you. She wondered why a placed PDF file — a CMYK image created in Illustrator — was changing its CMYK values upon output. After all, she was using Preserve Numbers in the Export PDF dialog box.
Preserve Numbers, both in the Print and Export PDF dialog box, is supposed to stop InDesign from changing CMYK values when the output (target) destination is different than the document profile. (Yes, I’m talking color management here. Wake up! Don’t glaze over!) However, in at least one instance, Preserve Numbers is ignored and you can get very unexpected results.
There is a very important lesson to be learned here about how InDesign handles color management: The settings in the Edit > Color Settings dialog box when you create an InDesign document affect your document forever, and in some cases it is a royal pain to change those settings later.
Preserve Profiles Defeats Preserve Numbers
I’m not going to go into all the gory details here, but suffice it to say that someone, somewhere, had the CMYK pop-up menu in the Color Management Policies section of the Color Settings dialog box set to Preserve Embedded Profiles instead of Preserve Numbers. This probably seemed like a good idea at the time to that person… You can just hear them thinking, “gosh, let’s be clever and preserve all the profiles!”
Unfortunately, “preserve profiles” is only clever if you control all the pieces of the puzzle, you know exactly what is coming and going in your files, and you’re on top of the printing/exporting process yourself. In this case, that person sent the file off to be worked on and printed elsewhere, and that’s where the problems started.
Because Color Settings were set to Preserve Profiles when the INDD file was first created, InDesign paid attention to the embedded profiles in all images placed in that file. “Paid attention to” is another way of saying, it recognized and honored the embedded profiles.
Technically, “Preserve Numbers” means “preserve the numbers in color swatches and images for which you are not honoring embedded profiles.” The result? Preserve Numbers turns itself off for all the CMYK images that have embedded profiles.
Avoiding the Problem
There are many lessons to be learned here. One is that you should probably just choose General Purpose in the Color Settings dialog box and stop trying to be clever. Notably, this ensures that the CMYK policy is to preserve numbers, not profiles. (See this post for more on why the sRGB setting in General Purpose also makes sense.)
Another solution to this problem is to not embed profiles in the artwork you don’t want changed downstream. In this case, if the PDF or AI file didn’t have an embedded profile, InDesign wouldn’t be able to honor one, and therefore Preserve Numbers would have worked. However, in many cases, this requires you to specifically turn off an “embed profiles” checkbox — or worse, convince an Illustrator or Photoshop user to turn those checkboxes off.
Resetting InDesign’s Color Policies
Okay, so you have an InDesign document created when Color Settings was set to Preserve Profiles. Unfortunately, InDesign doesn’t tell you that anywhere obvious. It took me a half-hour working with Carlie’s file before I figured it out. The only way to find out (that I can think of), and the only way to change it are:
- Open the document and choose Edit > Convert to Profile.
- Note the CMYK Profile setting in the Source Space section. This is the only way you can find out what the current CMYK profile is for this particular document.
- Click Cancel and close the document.
- Now, open Edit > Color Settings
- Turn on the Ask when Opening checkbox in the Profile Mismatches section.
- Make sure the CMYK pop-up menu in the Working Spaces section is set to something other than what the document cmyk is set to (the profile you noted in step 2). Just pick anything else; you can change it later.
- Click OK to close Color Settings, and now open the document again.
- You should see a Profile Mismatch dialog box. Notice that the Policy in the “as is” section is set to Preserve. That’s the only way I know of to see what the current policy is. [Note to Adobe: This is insane.]
- Choose “Adjust the document to match current color settings. (The policy you see should say Preserve Numbers.) If you don’t want your document to have the different profile you chose in step 6, choose a different one here. If you want to ensure that all the placed CMYK images no longer honor their profiles (that is, if you want to ensure Preserve Numbers will work for them all), then choose Disable All Profiles from the Placed Content pop-up menu.
- Click OK.
Now your document’s policy should be set to Preserve Numbers, and you won’t have the color-shifting problem with vector and raster images that have embedded profiles any longer.
To display RGB and CMYK policies and profiles of a document, you can write a script (better a JavaScript).
David, correct the following where wrong. (This is based on what I think you have said.)
Color Settings …, Assign Profiles …, and Convert to Profiles … are preferences that change things at the application level not at the document level. (They would be better placed in the InDesign Preferences.)
Setting these will only have effect on documents that are opened after they are set.
So to change a documents color profiles, it has to be opened in InDesign with different profiles from the opening document.
Andrew, actually Assign Profiles and Convert to Profiles do affect the current open document (and only that document). You can see this with the following experiment: Open any InDesign document, choose Edit > Convert to Profile, choose any other profile in the CMYK pop-up menu, and click OK.
Now look at the Swatches panel. You’ll see that most of your CMYK swatch definitions have changed! Convert to Profile actually changes the numbers of swatches.
Now, quick, close that document without saving it, so you don’t accidentally mess it up!
It’s very, very rare that you would ever actually click OK in the Convert to Profile dialog box, but it is useful as a demo.
In your post you mentioned that you didn’t know of any other way to determine the policy for profile mismatch. That surprises me very much, because you do discuss the “Ask when Opening checkbox in the Profile Mismatches section…”. Directly above these checkboxes are the pulldown menu’s for the RGB and CMYK policies.
/Users/arjen/Desktop/policy.png
An important menu if you’re concerned about colourmanagement, I think. Any externaly produced image is should be considered to be conciously designed and should be honored like that. The only way to have any grip on colour consistancy is to preserve the embedded profile (if any) and convert them when going to the press.
Yours truely, Arjen
Sorry, the image I tried to send, didn’t stick.
Arjen, are you talking about the CMYK and RGB pop-up menus in the Color Settings dialog box? Those affect future documents you make, but not the current document! Crazy.
David, crazy!. Embedding profiles is, as far as I know, especially to minimize colour differences. I fail to see why you wouldn’t assign or, later on, preserve the assigned profiles. Maybe I just don’t understand. So I think I’ll retier from this discussion.
Arjen, you are right that embedding profiles is important when trying to maintain color consistency. However, the assumption is that when you have created a CMYK file, you do not want those CMYK values to change.
For example, when someone specifies 50% cyan in Photoshop or Illustrator or InDesign, they usually want 50% cyan, no matter how it is printed. They care more about preserving the number than the exact look of the 50% cyan.
However, sometimes you may have a CMYK image from Photoshop that you care more about preserving its colors. That’s okay. Import into InDesign, and from the Import Options dialog box (or from Object > Color Image Settings), choose the profile you want to assign to it. If you do that, InDesign turns off “preserve numbers” for that one image.
The more I read what you write, the more I get the feeling you’d best turn off colourmanagement all together. Then you wouldn’t have to worry about profiles ever.
Even already color separated images from photoshop whithout even knowing who’s going to print according to what standard won’t keep you awake at night. Colour will differ from the orriginal anyway.
Arjen, I know the feeling! However, there literally is no such thing as turning off color management. InDesign (and other programs, such as QX) always do color management. Always. There is no way to turn it off, even if you see an “off” button. “Off” just means “do color management blindly, without telling me what you’re doing or letting me have any control over it.”
Using color in your documents is great, but it requires responsibility. Someone needs to take the responsibility for making sure that color works out right. In the old days, that responsibility was the printer or color house. Today, in most cases that responsibility falls on the shoulders of the designer/production artist.
There you have a point. And how does the designer tell the printer under which circumstances he meant the colour to be what it is meant to be, by including the file that tells him what these circumstances were, the profile. That way the printer will know what your 100% cyan and 50% magenta looked like when you were looking at it on your screen. Now he can reproduce that “feeling” on his press. Just reproducing these percentages on his press will probably differ from what you’ve seen on the screen.
For that same reason you will need to respect embedded profiles in photographs and artwork you will receive. Maybe you’d want to convert them to your own working standard, but DON’T just assign another profile to them because it will alter the colours. By converting to another profile, you might alter the way the colour is separated in cmyk, but the “feeling” (the intent) will be reproduced as accurately as possible.
Going back to the fist issue of this post, did the colour of the vector image change on output or on screen? Might be an important issue.