I bought my Twilight Zone fully LED'd and modded to the nines with blue lamps in the slot machine, skill shot, blue light along all the ramps, blue lights in the shooter lane, blue light under the backbox. It is sat next to a completely unmodded Addams Family which makes a pretty good side by side comparison as they ate both "black" games with similar overall design
It was far too blue and distracted from the artwork
Now this is all very much personal preference but here is my two penneth ....
My addams had the usual cracking under the mansion rooms. Use of cooler LEDs might have avoided much of this in the past. So this opens my mind to LEDs under the playfield from a game preservation perspective
Too much blue light on a TZ overpowers it, so I removed all mods from my TZ, apart from the gumball lights which I think are very discreet and really liven it up - especially with the marbles in there. And I left in the blue plasma disc light in the back right corner as this brightens up a dull corner of the game
The under playfield LEDs are a big improvement in my opinion, My tz playfield looks so much livelier than my addams. The contrasts are fantastic. The clear lenses in particular look so much whiter and crisper with LEDs. And i think this improvement works on a fantastic playfield like my tz, and on a more worn one like my addams. I have left one or two incandescent flash bulbs down there as the LEDs were too much under a clear circular lens (town sq)
I prefer the look of the incandescent lights with the coloured caps on (above the playfield) as these are clearly red or yellow, whether the light is on or off. Whereas the led ones are a milky colour when off
I think the LEDs are too powerful for the translite as some clearly show through as crisp spots of light. I like the whiteness of them, but it am either going to put lower power ones in there or replace with the original incandescents
I do not know where my LEDs came from, but I have had maddening issues with connections, in a way that has not happened in 15 years with my Addams with incandescents. The old glass bulbs have been far more reliable connections as they have terminals (sometimes a twin wire) on both sides of the bulb giving you two or even four chances of getting current through each side of the bulb. My LEDs only have one per side so I have endured maddening issues for a week or so, but have now bent them the right way. But I expect far more of this than with the better designed incandescents, so I anticipate plenty of glass removal in the future.
So a mixed bag really. But in the right places, and provided you do not go too bright, I am a convert