The original bulbs stay in, as the light up the dials as well as the pointers. I will just use the signal for the warning lamps for fuel and water and put them elsewhere. Not sure where yet.
As I already put the gauges back in the car I'll get some nice pictures when it's dark.
I'm ok with the result as I changed the illumination of the fog light switches to white. It would be perfect, if I could change the illumination of the a/c module to red, which is rather difficult, as it's printed in three coats from black to white to green. Just Putting red bulbs behind it would look rather strange.
The stuff which actually brings the red colour is this:
Phosphor coated paper which lights up. Needs a small inverter device which now sits behind the gauges.
The inverter is connected to one of the bulb holders on the back. The original dials are just stick-on and were removed.
I'll do more pictures when I put the new dials in. Still thinking of ways to make them look a bit different from the original ones.
Will also put up the images of the scanned original dials, in case someone wants to have a play.