First, sorry for suckering you into this thread with the cheesy Ebay Airsoft title! Ha ha!

But seriously...what type of clothing works better at night...light or dark?

World War 2 German night fighter planes were painted in a moth-like dappled light grey pattern on top with darker grey undersides; aircraft that used black did so mostly on the bottom because they were trying to hide in the black sky from people looking up from the ground. So, if you are on the ground instead of in the air, trying to conceal yourself from horizontal detection, which would be better? Something light colored like grey BDUs or the new ACU (or a moth!), or darker like  Woodlands or (gasp!) black BDUs?

The discussion parameters: This question presupposes that you are dressing SPECIFICALLY for night time action; the "use whatever you are wearing in the day" outlook does not apply here because this is a theoretical question.

The patterns that work best are the same patterns that work during hte day.  What is more important is the reflectivity of the specific materials and dyes you select.  

ETA that if you add night vision into the mix then you have to consider reflectivity in both visible and IR spectra.

No, I'm not taking IR night vision equipment into account.

I doubt the vermin will have that.

If you're too dark, you end up looking darker than the night. Hence why the Germans came up with their night fighter camo. Planes would looks blacker than the night. The best night color is apparently a pastel blue (see the original F-117 prototypes).

Anyway, I'd go with whatever works in the day. You'll get darker the same as everything else around you anyway.

A nice shade of gray.

ACU is its best at night.

ACUs... I would have to say as well, It's good stuff. Also, it's excellent for urban combat. ACUs aren't actually good for desert operations or woodland operations, but it's a good mix and works very well for urban environments.