Light Source Color

Light sources can have a color & intensity.
The default is full white.

The color of the light is combined with (multiplied by) the material color to get the final result.

• White light + red material = red
• Red light + white material = red
• Red light + blue material = black
• Yellow light + cyan material = green

    blue = [0.1, 0.4, 1, 1]
    glLightfv(GL_LIGHT0, GL_DIFFUSE, blue)