I completely replaced all the switchgear in mine with SAVAGE switches. This necessitated creating a complete new mounting and a whole new relay loom to incorporate independent relays for the flashers etc
There are several ways to do this. The main problem is that the orange colouring is done with orange plastic in the dials so any colours you change to the illumination will be muddied.
The cheapest and easiest method to get some different colours is to use EL (electroluminescent) wire of whatever colour you like glued to the inside of the reveal so that illuminates the front of the dials with a soft glow. I did this on my ZR early on in purple and have also fitted it to a few others cars. Heres a couple of examples.
There was a company who made a dial cover out of EL sheet which made the whole of the dial face glow and with the aid of a dimmer the colour could be changed between green and blue. I think Vic may have one of these fitted to her ZR?
Another option is to change the whole of the dials for something custom made. I approached Metal Monkey a few years ago to see if they could make me a set based on the R25 gauges. The R25 is mounted very slightly differently but eventually we came up with a set. The nice thing about these is that you can have virtually any colour, any font and any logo you like. These are mine
It depends on the quality of the EL wire. There is a lot of cheap stuff around that dosent last and also the colour and thickness affect the intensity as well as the quality of the inverter. I have had some in mine now for around 4 or 5 years and it is a lot less bright than before. That said it isnt that expensive and can always be changed. I get mine from www.litewave.co.uk