Photoshop color shifting when saving for the web

Yesterday, I was working in Photoshop and got a simple image looking the way I wanted it to. I had eyedroppered the color from a different file. Whenever I tried to edit in Image Ready or save for the web, the image became distinctly lighter. It would seem that this interestingly formatted page has the reason: Save For Web Color Shift ImageReady. As of now, I’m still seeing the color change when I move from Photoshop to ImageReady, so the tips presented there have not yet borne fruit for me.

A major issue here for me is that I’m trying to synchronize the color in the image with an HTML color. Photoshop tells me the correct HTML color code, but ImageReady is producing a different color.