Japan’s “Doctor Yellow” track-testing bullet train will be retired in January, its operator said Thursday, with plans for farewell events that will give fans a chance to thank the bright yellow shinkansen for keeping the country’s high-speed services safe also revealed. With the uniquely colored train having always run on an undisclosed schedule, it is considered a unicorn among the country’s shinkansen. This status means Doctor Yellow has been long said to “make people who spot it happy.” Central Japan Railway Co., which runs the inspection train on the Tokaido Shinkansen line, said it will n…