Illustrator Colour Wheel Settings: How to change the color wheel settings to show a full spectrum?

The Colour Wheel in the Edit Colors Dialogue Box (see image) is patches of colours instead of a smooth spectrum.

I'm looking to change the settings so that I get the smooth spectrum.

How can I do this?

What am I missing here? Why is the colour wheel showing colour patches instead of a spectrum (i.e. is this based on computer system, the application, the swatches I've chosen, settings in Illustrator?)

I'm using Illustrator CS5.x on a PC.

Thanks in advance for help and guidance as I am very new to Illustrator (but loving it!)