My first patch!

It draws the color of the lamp in the 3D view.

It is a per/lamp option, the button is in the preview panel.

In lamps type:
Sun: Inner circle, and sun rays.
Spot: Inner circle, and the circle/square at the bottom.
Hemi: Inner circle, and arcs.
Omni: Inner circle, and the circle (when in sphere mode).
Area: Inner circle, and the area.


Example:
http://www.venomgfx.com.ar/colorlamps.jpg

That's all, cheers!
venomgfx