Microsoft DirectX 8.0 (C++)

Colored Lights

The color-related members of the D3DLIGHT8 structure (Diffuse, Specular, and Ambient) are D3DCOLORVALUE structures. The colors defined by these structures are RGBA values that generally range from 0.0 to 1.0, with 0.0 being black. Although you will usually want the light color to fall within this range, you can use values outside the range for special effects. For example, you can create a strong light that washes out a scene by setting the color to large values. You can also set the color to negative values to create a dark light, which actually removes light from a scene. Dark lights are useful for forcing dramatic shadows in scenes and other special effects.