The 152 used to have this red colour in the interior when the lights were turned on, it was very odd.  It has been replaced with a more normal light colour.  I'll have to look at the other aircraft to see if they have had anything done to them.

 

They have (in my area at least) partially gone back to the way in used to be, using textures to light up the windows.  It looks much better than just the little splashes of light that were there before.

The 150 and 152 I flew IRL had red light.. red light saves your night vision. It may be old school? But it is realistic. 

All the old 172's I flew, N and M models, had red night lighting which let me see the dark mountainous landscape at night and also read my chart at the same time.

I thought it was supposed to be red because it doesn't have individual instrument lights? Red is less glaring so it doesn't blind you with night flying.

Older 172 have two light. One overhead and one to the left of the pilot side. Both light have red/white/off switch. At night I always use red.

Here is how it looks in action 

Yes, in reality that was one thing, but not in the sim.  I've only done day flying behind the controls of real aircraft, so I don't know exactly how everything works.