Hi Cecilia -
Several things contribute to the colors in this particular image.
First, the red tones around the edges of her upper thighs, mid-section and arms is coming from red light reflected by the heavy red drapes into these areas. The orange color cast to the left of the window and on the valence above is also due to the same mechanism.
Second, I suspect that the small blue areas on the floor and ceiling at the very top and bottom of the image were likely enhanced or even painted in manually.
The third, and, to me, the most interesting colors are the green and cyan tones in the shadow areas. These could be due to any of several factors. For example, a savy photographer could have intentionally set the white balance on his / her camera to be more green than a normal daylight WB to get this look. The same thing could also have happened entirely unintentionally because the automatic white balance system in many cameras would likely try to compensate for the reds of the drapes. However, in addition to the white balance factor, I suspect that the photographer used a technique called "cross processing".
This effect / problem was a real pain in the neck for old time film photographers, but it has resurfaced in the last few years as a very popular retro look. It pops up all over the place these days. For example, when one of the TV crime shows wants to suggest a gritty, low class or dangerous scene, they seem to always reach for the yellow-green cross processing effect. It has become so popular that some cameras offer this as a built-in effect. There is an iPhone App for it:
https://itunes.apple.com/us/app/cross-process/id355754066?mt=8
And, of course, the different variants of it can be done in Photoshop either by using the built in native tools or by third party add-ons such as NIK's "Color Effect Pro", onOne Software's "Perfect Effects", and similar products from Topaz and other companies.
I appended some examples of cross processing below, and here are some links to other examples of the look:
http://www.polkauk.co.uk/wp-content/uploads/2012/07/BeFunky_CrossProcess_121.jpg (a modified version is reproduced below)
http://www.lomography.com/magazine/lifestyle/2012/05/25/cross-processing-colour-guide
http://www.mora-foto.it/en/tutorials-gimp/two-strip-technicolor-effect/technicolor.jpg
Finally, here are some links to tutorials on how to do it yourself:
http://www.gimpinfo.org/tuts/cross-processing/
http://www.digitalcameraworld.com/2...-way-to-get-this-classic-effect-in-photoshop/
http://crossprocessing.info/
http://www.lomography.com/magazine/lifestyle/2012/05/25/cross-processing-colour-guide
HTH,
Tom