Have a look on Nasioc and Rexnet... this isn't a mod to do to your original cluster, you actually have to sand a thin green film off the back of the dial face. The tricky part is you can't really access it without removing the face and hence the needles which is a big no no for all your calibrations. People have done it with a long thin strip of sandpaper slid underneath the face whilst in place but its difficult to get even. After you've removed the film then yeah as before change the bulb colours or put condoms on to get the desired effect.

In summary, this is a do at your own risk mod and imo not worth the pain unless you have another cluster at your disposal.