I am not the author of this scheme. I've just adapted the scheme from Thinkpixellab for Sublime Text 2 available here.
To install it, copy the xml into the following directory (XX = your version of Pycharm) :
- MacOS X :
~/Library/Preferences/PyCharmXX/config/colors/
- GNU/Linux :
/home/USER/.PyCharmXX/config/colors/
- Windows 7 and newer :
C:\Users\USER\.PyCharmXX\config\colors
- Windows XP :
C:\Documents and Settings\USER\.PyCharmXX\config\colors