Color Blindness iOS 10 Settings
We routinely see Apple add new accessibility options with iOS updates and there is a new option for Colorblind users and users who have trouble differentiating between colors.
In Settings -> General -> Accessibility -> Display Accommodations -> Color Filters there are new settings for users to control.
When enabled users can toggle Grayscale as well as filters to address Protanopia, Deuteranopia and Tritanopia. Another option allows users to choose a color tint.
With three of the options users can also control the intensity of the filters to fit your needs.