Acrobat/Distiller Question

Hope, it's the right place to ask, so here it is:
I have some HUGE PDF files (and I really mean HUGE - some are about 17MB - imagine putting it on the web for downloads). I was told that to compress them here's what I need to do:
"I take the original brochure artwork (ours are done on quark) and export the
pages as eps files.You then drag the eps files onto the distiller icon to
convert to pdf files. Distiller gives you several options to convert your
files;
Screen optimized
Print optimized
Press optimized.
If the files are just for viewing on screen use the screen optimized
settings , this gives you a very small file size.
Print optimized is slightly better and a bigger file size.
Press optimized is for artwork use resulting in very large file sizes."
ok. that is quite clear and easy to follow. the ? is: why after the process do the colors change??? For, example, red becomes almost pink and a bright blue becomes a very light blue of a different shade. I tried to play with the settings, but nothing worked. I use Acrobat 4 on a MAC.
Any ideas?

Thanks

It's hard to tell without actually looking at the files, but my guess is the original artwork is in CMYK and when you convert it to an Acrobat file meant for "screen viewing", it gets converted to RGB. Try doing the conversion from CMYK to RGB before you save them as EPSF.

Good points ... plus, your monitor color calibration can actually affect the outcome as well. You'll probably want to use what is called the sRGB color profile, since its becoming pretty much the de facto standard on the web as a color space. Because of this, when you're designing in something like Photoshop's full 32-bit color space (but not calibrated to sRGB) then save something for web to the sRGB space, you can also see some color shifting between the .psd version and the .gif/.jpeg version, even when both are open in Pshop side by side.

cheers,
bob