Ah sorry I haven't been around to help out. I read about removing the backing of the cluster and was just hoping that ya hadn't done it already. TEST IT!. Put 3 volts (2 AA Batteries) into the LED (I rigged up a LED tester with an old battery pack for a toy that had wires coming out) and put it behind the face of the cluster. No green shows through at all. The blue is so bright, you won't see or notice any green whatsoever. Do NOT take the backing off the cluster. You will destroy it. The way I did works fine. But every part of it will be blue. Even the little red lines at the top of the Rev Tacho.
6x 5mm LED's - 5000 or 8000 MCD (brightness) - (and 6 resistors) needed for the cluster. For an SS (with the 3 trip buttons) you'll need another 2. So 8 total if you have the 3 trip computers.
I used 3mm LED's for the Air Con controls. You'll need 1 for each dial. If you want to change the colours of the lights when activating rear demist and A/C, get another 2. I forgot to do this so not sure how. You'll need the resistors for this too.
Sorry that my guide isn't here yet. I have all the pictures but no descriptions. I'll upload them tomorrow. Any other help, just ask. But I won't be home til tomorrow. Good luck and sorry of the delay.
azkwazere: It will be exactly the same. If you don't remove the backing though, a blue globe won't be strong enough to shine through blue. Do the same as mentioned here. Solder an LED onto a resistor, and solder both ends into the place the globe was. Just gotta make sure you do it the right way up.
When the cluster is facing away from you and right way up, the positive end is AT THE TOP.
Good luck.