Yes, ForeFlight has themes for both day and night. You can set the day and night app themes to your liking by going to MORE > SETTINGS > DAY SETTINGS or NIGHT SETTINGS. Once you have set up your day and night themes, there are three app theme buttons that allow you to change between either Day, Night, or Auto themes. When Auto is selected, the theme will automatically switch from day to night based on local sunrise and sunset times.
Image 1. Day/Night settings under MORE > SETTINGS.
Image 2. Day theme setting options.
Image 3. Night theme setting options.