The Silent Hill Movie featured its very own nurses; based on the Bubblehead Nurse from Silent Hill 2, the Dark Nurse resembles her in means of being another version of the disturbingly sexy, distorted-faced hospital staff. (Clicking on her right side will show you pictures of her back, clicking on her left side pictures of her front.)

Thanks to the making of the creatures, I got some decent screen shots of different style nurse faces as well as general pictures of the entire costume. As you can see, the faces of the extras are covered with a latex mask that looks like melting, rotting skin with no normal facial features. It has ridges and big, deep wrinkles, holes. Overall it looks like a really bad burn scar.

Their entire skin is gray-ish pale, with more or less dark veins and in some cases little speckles/splatters. Those veins are are more concentrated and visible on the head, the chest, the back of the hands and from the knees down. In some cases they are fine, dark lines, in other cases thick, soft lines in blue and red, and in other cases just barely visible. The front half of the fingers is blackened.

Dark Nurses wear a very skimpy dresses which according to the makers of the movie are supposed to be/look like rotting skin. The dresses seen in the movie were made out of latex, but I guess it should work to first make the dress out of thin fabric and then add layers of liquid latex or dragon skin over it until it resembles the texture of the movie dresses.

The hemline of the dress and the sleeves appear torn, the nurse hat too does not look sewn but made of rotting skin. I'd suggest to play around with fabric and liquid latex/dragon skin and mixed in tissue for the bumps and other details and see how all this works for you. The color of the dress and hat varies from nurse to nurse, but overall is a dirty light to dark beige with soft yellow, red and blue/green areas to it, giving it kind of the look of bruised, dead skin.

The nurses in the movie were the first Silent Hill nurses to wear high heels. These are off white and dirty with a rounded front. Non of the nurses wears shoes with pointed front!
Another thing to keep in mind is that the Dark Nurse too does not have any fresh blood anywhere, so try to stay away from it. This will make your costume look more convincing.