Select Settings > Display.

Auto Screen Lock

Automatically locks the keys when the backlight times out to prevent inadvertent key presses (Locking and Unlocking the Keys).

Color Scheme

Sets the device to display light or dark colors.

Brightness

Sets the backlight brightness. If you select the Automatic option, the device automatically adjusts the backlight brightness based on the ambient light.

Timeout

Sets the length of time before the backlight turns off.

Always On With Ext. Pwr.

Sets the power mode when connected to external power.