The idiom odd one out refers to someone who is different from everyone else in a group, which is what the context describes. 
Consider the statement "There were lots of people on the rim who had no idea, but now that he lived in the blueline, he was the only one who was different. ". Is the statement "There were lots of people on the rim with no idea, but now he lived in the blueline, he was the odd one out." false? Yes/no/unknown