When the user selects the light theme, the application's visual elements would be displayed with a light color scheme, which typically features bright colors and a white or light background. On the other hand, when the user selects the dark theme, the visual elements would be displayed with a dark color scheme, which typically features darker colors and a black or dark background.

Implementing this feature can improve the user experience of your application, as users can choose a theme that best suits their visual preferences and makes the application easier to use in different lighting environments.