sentences:  However, all trains passing through Kannai directly operate between Line 1 and Line 3.Due to the opening of Line 4 (known as the Green Line), the line has been marketed as the "Blue Line" since 30 March 2008; its origin came from "Blue" being a symbol of Yokohama due to its color (it has been used in vehicles and signs from the time of opening, since it is recognized as the image color of the route).The line color is blue and the line symbol used in the station numbering is B.