Using the Spotlight Presets Pack:

In your scene,
Choose File > Append,
Locate the ‘CGL_Cycles_Spotlight_Presets_Pack_1.0.blend’ file, and click it to browse its contents.

For using the Spotlight Presets Pack as a Blender Lamp, Choose:
Object > CGL_Spotlight
With the Lamp selected and active,
In the Properties > Data tab,
Choose the light beam style and set its parameters.

For using the Spotlight Presets Pack as a Circular Mesh Light, Choose:
Object > CGL_Spotlight_Mesh_Circle
With the Mesh light selected and active,
In the Properties > Material tab, under Surface,
Choose the light beam style and set its parameters.

For using the Spotlight Presets Pack as a Square Mesh Light, Choose:
Object > CGL_Spotlight_Mesh_Square
With the Mesh light selected and active,
In the Properties > Material tab, under Surface,
Choose the light beam style and set its parameters.

The CGL_Spotlight_Presets_Pack_1.0 parameters:

Beam Style:
Numerically select between 1 - 20 light beam designs.
* In render viewport mode you can simply scrub this value and see the light design change in real time.

Beam Focus:
A positive value will narrow the beam, and a negative value will expend it.
* default value is 0.0

Intensity:
The light intensity (strength)

Color Temperature (1 = 100 Kelvin):
Set light color by Kelvin color temperature.
* the value is divided by 100K for tweaking convenience (65 = 6500K)

Color Filter:
Set light color by RGB color selection.
* multiplied with the color temperature

Color Filter Weight:
The amount at which the Color Filter affects the overall color.

Chromatic Dispersion:
Add a chromatic dispersion effect to the light beam.