Invert screen colors and color correction
Go to phone Settings>Accessibility we find two very curious options to control the colors of the screen. One is ‘Invert Colors‘, this option turns the entire spectrum of colors that the screen represents. That is, we will see everything as the negative of an analog photograph.
The other option is ‘Color Correction‘. This is an option to help people with dichromatic color blindness (difficulty in distinguishing two colors in particular). This type of color blindness has three variants protanopia (red-green), deuteranopia (red-green) and tritanopia (blue-yellow).
When we activate this option the screen will show the color spectrum in which the colors that can confuse each type of color blindness are avoided.