I got hold of a LaunchPad "NOVLPD01"-interface recently and even if I could manage to use it as MIDI-interface, I could not bear the fact, that Reaper couldn't directly trigger the colors of the buttons.
So I sat down and reverse-engineered the MIDI-messages needed to lighten up my Launchpad.
So here it is: a small library of Lua-functions, who allow you to program the lights and colors of the buttons:
https://mespotin.uber.space/Ultrasch..._functions.lua
To showcase these functions, there's a demo-function called "LaunchPad_Show_Image_Demo()", which will allow you to select a picture, which will be shown with a scrolltext in a window.
Now move the mouse across the screen and the contents of the gfx-window from mousepointer to 8x8 pixels to the right and bottom from the mouspointer, will be displayed on your Launchpad as well.
You need to set MIDI-output to your Launchpad.
I have no idea, whether this works with other Launchpads as well, as I have only that one, but maybe it's of use for you anyway.
Feel free to use it for whatever you like, as long as you give me credit for the initial work.