Worst-case scenario: the UEd Goblin wipes the map and burns down your house.

From Unreal Wiki, The Unreal Engine Documentation Site

The Unreal Engine uses a HSV color space for specifying light colors. HSV stands for Hue, Saturation and Value. The hue specifies the actual color (red, green, blue, etc.), while the saturation specifies how colorful or gray the result will be. The value component scales the result between black and full brightness.

The following table gives an overview of LightHue and LightSaturation values you can use for light sources, such as the Light^{(RTNP, U1, U2, U2XMP, UE2Runtime, UT, UT2003, UT2004)} actor in Unreal Engine 1 and 2 or the LightComponent^{(UDK, UT3)} of actors in Unreal Engine 3. The third parameter, LightBrightness, controls the strength of the emitted light. As you can see, the LightSaturation is actually reversed, in that zero saturation actually produces a fully saturated color, while full saturation produces gray.