I have a large Indesign Document (about 200+ pages), and in about the half of the pages the images were copied & pasted into the document instead of linking them.
These images are now somewhat blue-ish when I view the exported pdf.
What could the reason be?
This is how it looks. The linked images are fine, because they were exported to CMYK in Photoshop before. How can I get the copied images to CMYK without linking them?
If I understand your question correctly, you've got an INDD document with a bunch of non-linked images pasted into it.
Got curious about this and figured out how to fix. Turns out you can get your image into Photoshop very quickly:
using the Direct Selection Tool in InDesign, click on one of your pasted images
open Photoshop and choose New... to start an empty document. The size should default to the dimensions of the image you've got on the clipboard (under Preset, it should show "clipboard")
Paste in your image and then hit Return to finish placing it.
If you look in your Layers panel, you'll see it as a "vector smart object". Flatten the layers.
Now, just go into Mode and change to CMYK, and save it somewhere. I'd save it as a TIFF so you don't compress it any more than necessary â€” and CMYK JPEGs are a mess anyway. You might want to go into Image Size and check that out too, to see how large these pasted images are.
Back in InDesign, you can now just click the picture frame with the Direct Selection tool and hit delete to empty the frame out (while keeping the frame so you don't break your layout). From there, just import the CMYK version you saved in Photoshop.
Well, 200 pages ain't that big. I wouldn't send that to print without remedying the pasted images. That can cause some strange problems -- like the one you're experiencing.
However, if you're the daring type, there is a convert color option in the PDF export dialog. You may end up with the same color shift or something completely new but you never know. That's the exciting part of breaking production rules!