EF_DIMLIGHT
EF_DIMLIGHT is defined as 0x004, or 4.
This effect creates a dynamic light with an RGB value of 100 100 100 and a random radius of 200 to 231 at the origin.
Usage
In code
Inside of the codebase, effects are defined as a bit-based enum and are stored in m_fEffects. This effect can be manipulated with AddEffects( EF_DIMLIGHT ), RemoveEffects( EF_DIMLIGHT ), and SetEffects( EF_DIMLIGHT ). This effect can be obtained with GetEffects() & EF_DIMLIGHT or IsEffectActive( EF_DIMLIGHT ).
In scripting
The functions mentioned above are supported in VScript starting with 
Dota 2 . They can also be found in 
Garry's Mod .
In a map
To use this effect in a map, turn off SmartEdit mode and add the following keyvalue pair to the entity: effects 4.
Note:If it is desired to use this with other effects, you should add the integer value of each effect to the value.You can set the effects keyvalue during runtime using AddOutput with the input value effects x (x being any summation of effects flags to enable).
Warning:Using AddOutput to change an entity's effects may interfere with an entity's simulation functionality.