This light value represents one of four different light sources (0 - 3). The series of values represents the RGB color values for the ambient light. The first three numbers represent the RGB values respectively. The numbers are somewhere between 0.0000 and 1.0000. 0.0 0.0 0.0 represents black, while 1.0 1.0 1.0 represents White. The last number is always set to 1.0.
Entry Name: Light0_Ambient, Light1_Ambient, Light2_Ambient, Light3_Ambient
Entry Type: Character String that specifies the RGB color Intensities. The default value is 0.0000 0.0000 0.0000 1.0 (Black).
Ambient illumination is light that has been scattered so much by the environment that its direction is impossible to determine - it seems to come from all directions. Backlighting in a room has a large ambient component, since most of the light that reaches your eye has bounced off many surfaces. A spotlight outdoors has a tiny ambient component; most of the light travels is the same direction, and since you are outdoors, very little of the light reaches your eye after bouncing off other objects. When ambient light strikes a surface, it's scattered equally in all directions.