I noticed that when I open a graphic in Illustrator and Photoshop, the
same CMYK value appears with different RGB values. The colors come up
with different color numbers as well for the same CMYK value.
I need to put these graphics into Word and Powerpoint, which only take
RGBs, and I would like to make sure that the same RGB color is truly
the same, no matter which program the graphic was created in.
I am not well-versed with any of this and would also be glad to hear
of links that address using colors in general.

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Request for Question Clarification by smudgy-ga on 14 Aug 2004 04:46 PDT

Hi jimwest,

Are you planning to make physical prints of your images? If not, you
might be better off sticking in RGB mode throughout your image
development cycle and avoiding CMYK altogether. CMYK is really
designed to take into accounts the limits of color printing
technology, so you might get numerous different (particularly bright)
RGB colors that get "grayed out" to the same CMYK value.

That being said, I've found plenty of information on the relationship
between RGB and CMYK. If you could be more precise about what kind of
information you're looking for, I'd be willing to cull out the
relevant material and post it as an answer.

Thanks,
smudgy.

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Clarification of Question by jimwest-ga on 14 Aug 2004 09:20 PDT

Yes, I will need to print these graphics from Office applications like
Word and PowerPoint and from Quark as well. I believe that the
graphics have to be in RGB for the former and in CMYK for the latter.

You're going to have a lot of difficulty maintaining an accurate color
printout from Word and PowerPoint.  Many programs have different
"color spaces" (ways they convert and show colors).  Adobe allows you
to select a different color space for each program.  Microsoft
products don't even allow this.

My suggestion is to print out the CMYK file from Quark and/or
Illustrator and then make a series of various RGB conversions in
Photoshop and print them out.  Then, see which best matches the CMYK
and use that in the Microsoft programs.

--Joey

The key to print out accurate color out of Microsoft products is to
save the CMYK image file as a TIFF. Unlike the JPEG and GIF format
that are RGB information, the TIFF maintains the CMYK information of
the image. Microsoft says that Word will accept the TIFF format,
though there appear to be ocassional errors associated with it. One
limitation is that the TIFF has to be saved as an 8-bit image. The
following articles might be helpful:

Descriptions and Limitations of Microsoft Word Graphics Filters
http://support.microsoft.com/default.aspx?scid=kb;EN-US;290362

TIFF Image Is Not Displayed As Expected
http://support.microsoft.com/default.aspx?scid=kb;en-us;294854&Product=wd2002

Apple has a clear and brief explanation of Color Spaces and the
relationship between computer monitors and devices
http://developer.apple.com/documentation/mac/ACI/ACI-48.html