• brightness to set how significantly the light should illuminate the objects.
• range to define the max distance at which the objects get illuminated.

Open question: should these settings be available in flight?

can you also maybe add support to edit light colour in flight. would be awesome.
trying to make a display. using kos.
also no way I am gonna go change brightness settings one by one for all 450 lights. in the vab.
can you add that to in flight pls pls pls.

As far as I can tell, the issue in this case is not the brightness (or "intensity" in Unity terms). It's the light range. Now, it can be controlled (see: #4).