How to > Advanced features and topics > Settings > Change any light's brightness
  
Change any light's brightness
1. Open the Lights dialog box.
2. If necessary, enter the number of the light you want to be active in the Light box.
3. Enter a value for the brightness in the Brightness box. The allowable range is 0.0 to 1.0 (0.0 is off and 1.0 is full brightness).
The default brightness for a light depends on its current color.