I have the same gauges in my Laser. Right now they are hooked up "wrong". With the daytime running light circuit in effect the lights are always amber unless the car is off. Granted, the white gauges are easier to see in the daytime but too bright at night. Eventually i'll probably do something with the way the lights operate but for now the amber is fine.
I was thinking of changing the daytime running light circuit or just putting in a rocker switch to change between amber and white when I want.
Funnily enough, every once in a awhile one of the gauges stays white while the other is amber. If I turn off the car and restart it the gauges will both go to amber.
Also, I do believe I did a direct ground to the chassis..... can't remember why..... but I do know that I didn't bother with dim-ability at the time. Maybe i'll have another look at where I hooked up and why when I get a sec.