Open the Settings app
Tap Display & Brightness
Choose Light or Dark mode
Tap Accessibility
Tap Display & Text Size
Adjust Color Filters if needed
Tap Back
Tap Wallpaper
Select a new wallpaper color or image
Tap Edit on a photo in the Photos app to change its color appearance
Use the Markup tool to draw or highlight in different colors
Change app icon colors using Shortcuts if desired
Open Control Center and adjust True Tone or Night Shift if needed