Now that I have the pinball machines all in a row, and my home office doesn't look like it is from an episode of "Hoarders," I can get back to my underlight project. Here's my color test on the Bride of Pinbot machine.
I am using the FastLED library to animate them. I found a cool fire effect library that seems to work well. I just changed the palette from the fire colors to BOP (Bride of Pinbot) colors. The lights I usually use are GRB, but these holiday style lights are RGB. So, it's just a minor one line code change.
The actual lights have an adhesive backing and will stick under the machine. I use the 30 LEDs/meter version with the black backing and IP67 waterproof version. I like the IP67 Silicon glue effect and the black backing for a better show and protection from damage when moving a machine. The computer is an Arduino, and I've been working with a few different power supplies to get 5V at 10A to power the Arduino and ~120 LEDs.
If anyone reading is a better programmer than me, which you probably are, let me know if you want to help me get better fades and effects.