… You can sorta do that. Let me hunt down the link to the adafruit wireless LEDs.
The problem is they’re really heavy. I can 3D print a drone propeller pause it in the middle embed an incredibly light 1.5x1.5 mm LED in the tip of all three blades…
A 3.7 volt coin cell from an RTC would be embedded in the top center of the shaft. a single point tiny brushed connection would carry the data signal to the propeller.
You could do this probably for anything but the smallest of quads…
It would also be entirely waterproof