CMYK vs RGB

[tee3327]

I am illustrating a book and making the images in Illustrator.  My page set up is cmyk, I've changed my color mode to cmyk, yet the publisher says my colors are still RGB.  My colors are not restricted to CMYK, and I don't know how to get them there.  I need my colors restricted to just CMYK but do not know how to get Illustrator to do this.

[Larry G. Schneider]

What is the file format that you are using when saving the AI files?

[tee3327]

png

[Larry G. Schneider]

PNG is a raster format that will always be in RGB. Try using a PDF which can be CMYK.

[tee3327]

But while working in Illustrator, my colors are not restricted to just cmyk, so how do I know if the colors are correct.   I'm not really sure if I'm asking the question correctly. 

[Monika Gause]

Why do you export PNG?