1) I believe the "printer" in this case is the Acrobat Distiller. Since Illustrator and Acrobat are both part of CS5, I assume they are configured to work together. So you suggest that Word is unlikely to display colors the same way as these two apps. That's exactly the question I'm asking. Yet when I output a color encoded by Word, it appears in the pdf correctly. It's only when I import an eps image that the color shifts.

2) Illustrator tells me it is in RGB color mode. I don't know whether it is producing 8-bit color. How can one determine that?

3, 4) The on-screen representation is similar to the printed output. That is, the two colors do not match.

So, I still don't understand where the problem is.