The trouble with technicolor films from Sweden is that they are all back and white. It started with Wallender, but I am currently working my way though a series of foreign thrillers with English subtitles. As someone reared on Morse, Frost and Taggert, I find these continental thrillers much more brutal and callous, but also more convincing. The evil is more evil and the good guys, flawed, but more believable.
The Girl with the Dragon Tattoo is the first of the Millennium trilogy and I recommend it to those who won't be offended by scenes of rape and murder. Sadly these things take place in our society; they are painful to watch, but lest we should be soft about the perpetrators, it is as well to remember why we have the death penalty and why prison means punishment.
The French series, Spiral, is equally gritty and takes the evil into high places. From what we have recently heard about France corruption reaches into the very heart of government.
There is a Danish series entitled the Killing, which I have yet to watch, but I have it on my list.