I took my cluster apart on my '64 Skylark, painted the backshell with "UV" paint.
(Wildfire Invisible blue maximum)
Then used Superbrightleds.com UV bulbs for the backlight illumination and it gives a nice bright blue illumination to the white numbers/lines and the orange speedo needle is very bright. It is easy on the eyes at night, and plenty bright even with city light glare.
For the Gen/Oil/Temp/High beam indicators I used red LED bulbs.
For the turn signals, I tried the green but they were way too bright, (53 lumens) so I used regular 194 incandescent and they are fine for me. Since they are only used for short interval, the current draw is negligible. I think the 15 lumen green LEDs might work (below).
(UV backlight 194-UVHP5)
(Red indicators 194-R3HP: Red)
(turn signal indicators 194-G3HP
When you have a colored lens, the colored LEDs provide a even lighting, if you use "white" LEDs, they tend to show "washed out hot spots".
Hope that helps. :)