No, the dimensions don't change but the width of the colour lines will sometimes deviate which bugs the hell out of me. I prefer to use color to make the electrical/plumbing more user friendly to the client but i'll resort to black and white plans if I absolutely must.
I generally use specific output generators in my CAD/EDA systems that produce hierarchical .pdfs from the structure itself. turns out to be incredibly handy. That said, I have had a number of issues with the print output converters that essentially pdf the output stream. In those instances, usually some experimentation with the available printer languages that it will be converting yields some better results.
my 2c..