In my W201 (which uses the same wedge bulbs as the 124) I used Raybrig "blue/white" bulbs and put in the white cluster faces. The result, even with the white faces, was not great. It's still difficult to read the trip odo at night. The problem is the reflective plastic used to "conduct" the light to the gauge faces. I have purchased a 10 LED array that I'm going to install at the top of the cluster shell and wire them to the bulb holder so that the rheostat will still dim the LEDs.