screen displays only greyscale
The iPad Air screen displays only greyscale: third time of occurrence. On previous occasions it has just returned to normal. Machine still under warranty/Applecare
iPad Air, iOS 8.4
Try going into Settings > General > Accessibility and see if Greyscale is set 'on' - and check to see what Accessibility Shortcut (i.e. a triple-click of the home button) is set to at the bottom of the Accessibility screen