There are a multitude of different types of lights available in Source. Learning how to use each type of light is very important in setting the mood in your maps. Every type of light entity has its own special properties that help define the look and feel of the map's lighting. However, most light entities have a common brightness parameter that controls not only the brightness but also the color.

The Brightness parameter contains four three-digit numbers separated by a space. The first three numbers specify the color in Red, Green, and Blue (RGB) format, while the last number specifies the light brightness. The default brightness is 255 255 255 200, which is a white light with a brightness of 200. Hammer has a built-in color picker, so you don't have to mess around with the raw RGB numbers, although it makes copying and pasting colors from outside applications easy. There is no specific unit for the brightness number. Higher values are brighter, whereas lower values are dimmer...