Developer Steve Troughton-Smith has posted a screenshot of the reference on Twitter which reads:
"NetworkNo4KForYouSubtitle" => "Your Internet connection speed might have dropped below 15Mbps, there could be a problem with your home network."
Troughton-Smith also discovered a list of color profiles supported by the new Apple TV which include:
● Dolby Vision
● HDR-10 4:2:0
● HDR-10 4:2:2
● HDR-10 4:4:4
● YCbCr 4:2:0
● YCbCr 4:2:2
● YCbCr 4:4:4
Apple is expected to unveil the new Apple TV at an event on September 12th. Please follow iClarified on Twitter, Facebook, Google+, or RSS for updates.