If you want to replace a colour in the selection (in Gimp 2.2), you should use the 'Color Exchange' filter, under 'Filters -> Colors -> Map -> Color Exchange'.
Unfortunately, I don't think there's any way to 'eye-dropper' the TO and FROM colours, but if you select the colour as the foreground, you can just copy the color settings (using the hex entry would be easiest) across to the filter. You can also set thresholds for the 3 colour channels to make it less picky about the source colour.
Since you mentioned texture, if what you really want to do is actually keep texture and just change the overall colour of something, you could try using the 'Colorify' filter, or the Hue/Saturation tool.
Hope that helps.