Amazon launched four new Kindles this week, maybe the biggest single launch day in the 17-year history of the company’s wildly successful e-reader. One of them even comes in color! It is very much not a coincidence that the launch happened roughly a year after Panos Panay joined the company. Panay, a longtime Microsoft executive who was for years in charge of all things Windows and Surface, is now leading the devices and services team at Amazon. His big task is Alexa, and turning…