Dropped Tablet and Now Screen Has Inverted Colors (Did Not Crack)

Hi everybody, thanks for all the useful answers. I have the same problem except my tablet didn't fall. I've tried searching the SETTINGS menu, then ACCESIBILITY tab, but there's no VISION tab, hence, no INVERTED COLORS tab either. The Android version is the latest (4.4) so I can't see where the problem is. Other than that, the tablet is working fine. Any help with this? Thank you so much.