They shoot L&O SVU with Arri Alexa(s); it might really be night! This camera has a nominal 800ASA and goes all the way to 3200 with relatively little noise/grain. There are many movies and TV shows that shoot on film, but use Alexas for the night shots.
There is no painting in the camera; it was shot on Arri C-Log and color corrected in post. The camera has an 709 LUT built in so that the director can see a very good one-lite approximation of what it will look like in TV color and gamma, but the 12-bit 444 ProRes recoding (on SxS cards) gives post lots of room to play.