Why Does My CMYK Illustrator Document have a 4-color Default Black?

For months now, I have been plagued by an unusual Illustrator problem: 4 color default black. I've always been told pressing the letter D will revert the fill and stroke to their default colors. Like so:

Illustrator default black

But I have a vast collection of Illustrator documents which have a different default black. Instead of getting the expected result of 0, 0, 0, 100, Illustrator gives me this:

Mysterious 4-color default black

Early on, I assumed that perhaps I had made an amateur mistake of working in a RGB color space for my print documents. But nope.

I thought perhaps somehow the default black had gotten edited within the Illustrator master templates, so I checked those. But those all had the correct black definitions as well...

What plagued me about this problem was that it occurred on ALL the files for a particular project, and NEVER for any other project. So I figured that since all the files for this particular project were created from a single Illustrator template, the problem must be within that template. But all was seemingly correct with the template. It was a CMYK document, with CMYK swatches. What was interesting about this version of 4 color black was that it appeared to be a CMYK representation of an RGB black.

So, out of curiosity, I started at the beginning of the lifespan of a file, and created a bunch of new documents, using all the different New Document Profiles. Eventually, I was able to replicate the problem. The problem can be replicated by creating a new document using one of the RGB profiles and then changing the Color Mode (in the lower "Advanced" portion of the dialog box) to CMYK.

You see, you can use any of the new document profiles to create a CMYK document. The new document profiles come with a default color mode. But you can change it to whatever you want! However, these New Document Profiles correspond with actual .ai files that Illustrator uses to create new documents. Adobe has a good writeup about new document profiles here.

So if you start with an RGB file and simply change the document color mode to CMYK, Illustrator still remembers that the files started out as RGB. But since you changed the color mode to CMYK, Illustrator assumes that you want CMYK swatches, so it reinterprets those original RGB swatches and displays them as CMYK. 

So after months of wondering, I finally figured out the original source of the problem.

• I opened a screenshot (which is an RGB raster image) in Illustrator in order to trace it.
• I changed the color mode from RGB to CMYK.
• I added my own CMYK swatches and symbols.
• I saved this file as a template and created hundreds of other files from it.

But Illustrator still remembers that the original file was RGB. Of course, the original file as a screenshot, and had no swatches of its own to begin with. But it was RGB. And so forever more, this file, and all of its descendants, have a four-color black as their default.

So, the moral of the story is:

• If you have a CMYK workflow, don't open an RGB raster image in Illustrator. Instead, place the image into an new CMYK document.
• Alternatively, you can open an RGB image in Illustrator, but be sure to copy and paste it into a new CMYK document.

Author edit on 2-19-13: I recently included this at a lesson of the Raleigh InDesign User Group. Here is a video illustrating this blog post.