Voice claim is Hong Kong from Hetalia

457 lives in a monochrome world thats literally black and white. In the medical field nurses are given numbers to help identify and remember them easier. 457 doesn't remember his real name anymore since that's all hes been called. For the majority of his life he was like a robot. He didn't feel any emotions and only focused on his goal of becoming a nurse. One day his life got turned upside down when he accidentally heard Venna playing music. The song had so much emotion put into it for the first time in his life he felt something and somehow gained color

Ever since then he and Venna have been on the run trying to figure out what's going on. Sometimes his skin color will become colorless when he isn't feeling anything or dread