This is a continuation of @BigNose's Aviation Lights mod. Instead of making him or a moderator update the title every time I update the mod, I'm (finally) starting a new thread.
The Aviation Lights mod provides aviation lights that may be used for providing standardized markers for airplanes / spaceplanes:
However, this being KSP, you can use them however you see fit.
Version 4.0.0 introduces a very configurable new light from @Stone Blue - you can tweak the housing, the l