Have used WS2812B RGB pixels quite a bit.
I have mounted an Arduino ~2 meters (I believe some have had luck at 3 meters) from the 1st pixel.
You can use 'none lit' pixels as repeaters to extend the usable length.
Can run several branches on one Arduino.
A single pixel can be controlled.
Up to many meters, 3 bytes of memory per pixel.
Powering can be from either end of a string.
One could cut 2, 3 or 4 pixels from a strip (maybe tissue paper on top), place them under a translucent clear plastic leaf with engraved veins, go a foot away then repeat . . .
Cut leaves out with a scroll saw or CNC router, sand surface with 600 grit sand paper.
Use heat gun then bend to give them a none flat appearance.
I have not tried this, you should be able to run strings in parallel.
They would light up identically.
(Just tested this, it works well)Hell, maybe use real branch material cut in half.

