I don't want to pay for a new instrument cluster just to get the tranny temp. I read that the Denali gauges light up blue. Has anyone changed the color of the lights to get a fresh look, such as red or blue? I know how to pull out the cluster, but I don't know how the illumination works. Are the gauges backlit? There doesn't seem to be enough space in front for anything else. Are the instrument markings see-through or lit up in some other tricky way? Are there different color lights that can be substituted? Anyone tried this? Is it cool?