Apple I-phone 5 S: I just down loaded the newest version of I-OS7. Phone screen went to inverted colors or looked like it was a negative. The first fix of tapping the Home screen three times did not work. I then went to 'Settings', then 'General', then 'Accessibility'. Once there there is a heading labeled vision. Look in that column for the Invert colors button. Its probably turned on. Tap it to turn it back to normal.