Big changes are coming to the Apple TV as it is testing a new technology that will be able to support 4K video with more vivid colors and exiting picture quality. Right now, the Apple TV only outputs at 1080p full HD, which is good enough and offers remarkable viewing, but it is not 4K. The Apple TV was last revamped in the later part of 2015 and it came up with beefier hardware, a refreshed tvOS interface and the Siri Remote, Apple's set-top box has basically weakened due to competing…