There are two ways to go with these dials: dark face with light numbers or mine with black-out applied to the back side in areas that you don't want illuminated. I will probably do a more comprehensive backside black-out eventually even though I rarely, if ever, ride at night.
The stock face plate, in spite of its questionable graphics, is a very sophisticated piece of laminate that redirects light in totally mysterious ways. Not something easily duplicated . The Websiinger 'Poly Film' is uniformly translucent with uniform colors, more so with lighter colors.[/QUOTE]
I worked in Aircraft Instrumentation for 15 years and when I recondition dials due to back lighting issues I had to Black out what wasn't being illuminated and on some dials it was easy. I would just use pin striping tape or even pin striping you get from the auto parts store on areas to be illuminated and paint the back of the dial black and on white faced dials were painted with white paint before it was painted black then remove the pin striping tape and those areas are now the only areas to be illuminated. funny thing is most of the paint we used was water based MIL Spec (exterior house) paint so not to have an bad reaction with the dial paint or the material that the dial is painted on, beleave me the wrong paint can act like paint stripper (did that once) so be carefull if you use paint