Amazon is introducing redesigned versions of the entry-level Kindle, Kindle Paperwhite and Kindle Colorsoft today, with slimmer bodies and quicker access to books. Each is one millimeter thinner, and book-opening speed has improved by 30 percent.

The devices now have their power controls on the right edge rather than underneath. The launch also brings new colors and a cover equipped with buttons for turning pages. Further details are expected as the story develops.