I receive PDF files everyday, and some have greyscale images that show up as cmyk. if I import the pdf into indesign, it appears as greyscale! Why is this happening, and how can I fix it?

It’s all about colour management.

The object’s source ICC profile is Dot Gain 20%. The Output Preview window has a Simulation ICC Profile of U.S. Web Coated. So the “preview” is a colour managed conversion from ICC grayscale to ICC CMYK.

Depending on workflow and or RIP settings, the grayscale object may or may not be converted to CMYK, it depends.

If you removed the grayscale source profile, then the object should preview as K only with no CMY.

If you changed the simulation profile from CMYK to Dot Gain 20%, then the image that was previewing as CMYK would now preview as K only… However other elements on the page may now show converted, not actual values!

Countless users have been “misled” by their lack of understanding of how this tool works.