Hex Color Shifting

OK, here's a tech question fer ya:

Have you ever had the problem of being off just one decimal in teh hex and
wreaks havoc with images against the background?  To explain:

I select (checked this twice) 102-204-255, which is #66CCFF, for my color
background in my jpgs and then use the same #66CCFF for the background of
the page.

What is happening is that the saved jpgs (50% compression) are shifting the
color by 1, or now 103-204-255, which of course shows slightly lighter and
obvious against the background of 102-204-255.  Is this inevitable with
compression?  I haven't run into this before....or could this be something
else, and how do I correct it?

I am using ImageReady, which is supposedly exactly how it works in Photoshop.  
Chris Hawkins
Author & Web Architect
Home Office: 520-795-9979
 	
	*	*	*	*	*	*     *
The idea is not [only] to make art, but to be in that wonderful state which
makes art inevitable.  

				-- Robert Henri and [CHRIS HAWKINS]

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