How to change the wallpaper and accent colours on my Nothing Phone (1)?

The wallpaper and accent colours can be changed by long pressing on an empty space in the homescreen, and selecting "Customisation" in the pop up menu. Tap on "Wallpaper & style" to select your wallpaper and accent colour. By default, Phone (1) will deploy Android 12's new Dynamic Colour feature to extract colours from the wallpaper unless specified.