How to Get an iPad Out of a Negative Color Effect
Any iPad running iOS 7.1 includes an Invert Colors feature that produces a negative color effect on the iPad screen. This accessibility feature makes text easier to read in low-light environments and reduces eyestrain. The feature is particularly helpful for fully or partially colorblind users. Some apps contain a separate feature that effectively accomplishes the same thing, although the result is usually black and white.
Disabling Negative Effect
Switch between apps to confirm that the negative effect is applied to your entire iPad and not just a single app. If the effect is systemwide, open "Settings," "General" and then "Accessibility." Slide the "Invert Colors" option to the Off position to exit the negative color mode. If it only affects one app, look for a setting in that app that switches to normal view. As an example, many ebook apps contain a night mode that employs a white on black theme.