I'm experiencing a problem with the colors when exporting to PDF. The issue was first experienced in an extensive project but now I'm able to reproduce it at will with even the simplest design. When I export a map or a layout to PDF, the color of symbols gets duller. It is very similar to what you'd expect if screwing up the color management in a photo project. So far I've only seen the color change on vector symbols, not their labels, and not on the underlying raster.
Try for yourself and see if you also have this issue.
Create a new map with a Basemap of your choice.
Create a file geodatabase with a few points.
Let the symbol be the default filled circle.
Fill it with a bright color - e.g. RGB(0,0,255)
Label the point feature and choose the same color as you used on the symbol fill
Export the map to PDF
Open PDF in Adobe Acrobat
Try to determine if the color is the same on the label and the symbol.
To determine the colors above, I pasted a screenshot of Adobe Acrobat into Photoshop and read the RGB.
Both colors were set to RGB (0,0,255)
In photoshop they are read as RGB(0,0,255) and RGB(53,82,165). The change from (0,0,255) to (53,82,165) is very similar to the one seen when converting an image from sRGB to the FOGRA39 (CMYK) color profile.
I've only seen this issue on PDF export, however, I've not done extensive tesitng with the other formats.
Please give a shout if you are able to reproduce the error and if you find a solution.