I have been looking for years for a short science fiction story about a man who was released from a prison planet in order to assassinate a candidate for galactic president. He does this on a space station, and escapes with the help of a mysterious and very attractive girl with silvery hair and multi-colored skin. The assassin was released from the prisoner planet by some influential people so that he may assassinate the galactic president candidate, whose rule would, according to said people, be bad for the galaxy. I also remember that the girl, who is more a young woman, is a prostitute, and the first time he sees her walking into the bar, she is accompanied by another man. I don't remember why she helps him. She was likely his contact, given to him by those who sent him on the assassination. They escape together, after creating a diversion with an explosion, running of into some corridor, that probably leads to a way to leave the space station. The story story ends there, and in my opinion, leaves room for a sequel, even if only to explore the protagonists' developing relation. I read this short story some 5-6 years ago online.