Try moving the glLightfv call after the glRotated call and see what happens when you spin the cube. Move it back when you are done. Setting Material Properties When you enable lighting, the glColor call no longer has any effect. Instead, we move to a different model for color of an object. Diffuse reflection reflects light in all directions, regardless of where it came from.
Specular reflection reflects more light in the mirror direction.
A perfect mirror has no diffuse reflection and tons of specular reflection. Perfectly flat paint has diffuse reflection and no specular reflection. Most things are in-between. This is generally the property you'll use to set the color of a surface. Systems like OpenGL only directly simulate light coming from some light source.