If you know that your primary light source will be a torch, you don't want a color scheme that calls for purple light. If your character has green skin, you may not want to use a green background. The hues of objects and characters should not limit your use of color, but should be factored in as you create a color scheme. By carefully coordinating the colors of objects and lights, you can add to the visual impact without detracting from the realism. In computer graphics subtlety is not always desired.
Color can create a dramatic effect as well.
When the aesthetic of your scene is stylized, color can become a tool of pure style, painting your objects and lights in bold strokes. Your choice of hues may entirely alter the emotional mood of an image. One dramatic effect is to change the color of the lights in direct relationship to the emotional state of a character. The scene begins with the character appearing calm, bathed in blue light. When an element of discord is introduced, the light shifts to red and then to yellow as the problem is resolved.