Aside from this:
http://www.subsim.com/radioroom/showthread.php?p=807655
There is a way to change the color the interior lights, seperate from the interior dat file via a shader file (I don't remember which one), however, as i said, it is separate from the interior file. I tried to get the light color to be more of a yellowish tint like SH3 instead of white, but the lights, and interior color are seperate. In other words when i tested night time lighting after changing the lights to look more realistic, i had yellow lights and red interior. I think the devs left the light shader white because it takes on the color of the interior that way.