I have written this tutorial in accordance with the request made by simonxp but I am sure that it will come in handy to others also .
This tutroial leads to a result similar to this image:

1. Open a 256 by 256 px transparent background document.Select the Shape Tool (U) and make these settings in the Options bar:

2. Create a circle covering about 90% of the canvas , place it at the center (X:128 , Y:128) and name this circular shape layer as Base.
3. Go to the Blending Options of Base layer and set these settings in their respective options:


4. Keeping Ctrl key pressed , click on Base layer in the layer palette to load its selection and then create a new layer (Ctrl+Shift+N) , name this layer as Shine.Fill the selction on the Shine layer with any color.
5. Set the Fill Opactity of Shine layer to 0% then go to its Blending Options and make these settings:

6. Create a new layer (Ctrl+Shift+N) and name it Rainbow.Get the Rectangular Marquee Tool (M) , draw a rectangular selection and place it at the center , fill the selection on Rainbow layer with any color.
7. Go to the Blending Options of Rainbow layer and set these settings:

Tip: With the Move Tool (V) selected , you can adjust the position of certain Blending Options which include Drop Shadow , Inner Shadow , Bevel & Emboss and Gradient Overlay .
For the Rainbow layer , adjust the postition of Transparent Rainbow gadient for the colors you prefer.
8. Create a new layer (Ctrl+Shift+N) and merge it with the Rainbow layer.With the merged (Rainbow) layer selected , go to Filter-->Distort-->Pinch and make these settings before applying the effect :

Press Ctrl+F two times to apply the Pinch effect twice on the Rainbow layer.
9. With the Rainbow layer selected , go to Filter-->Blur-->Gaussian Blur , before applying make these settings :

8. Reduce the Opacity of Rainbow layer to 35-45% . Press Ctrl+T and rotate the layer to an angle of 45 degrees . With the Rainbow layer still selected , Ctrl+Click on the Shine layer and press Ctrl+Shift+I to inverse the selection , press Delete key to delete the selected part of the Rainbow layer . Now your document would look somewhat like this:

9. Create a circle about 45% the size of the Base layer with Circular Shape Tool (U) having any color and name it Ring . Place the Ring layer at the center of the document, set its Fill Opacity to 0% , go to its Blending Options and make these settings in the respective options :



10 . Create a circle about 80% the size of the Ring layer with Circular Shape Tool (U) having any color and name it Ring 2 . Place this Ring 2 layer at the center of the document, reduce its Fill Opacity to 0% , go to its Blending Options and set these settings in the respective options :


11. Create a circle about 75% the size of the Ring 2 layer with Circular Shape Tool (U) having any color and name it Ring 3 . Place this Ring 3 layer at the center of the document, reduce its Fill Opacity to 0% , go to its Blending Options and set these settings in the respective options :

12. Create a circle about 50% the size of the Ring 3 layer with Circular Shape Tool (U) having any color and name it Ring 4 . Place this Ring 4 layer at the center of the document, reduce its Fill Opacity to 0% , go to its Blending Options and set these settings in the respective options :


13. With Pen Tool (P) , make a selection like this :

Create a new layer (Ctrl+Shift+N) and name it Gloss , keeping Ctrl+Alt+Shift keys pressed , click on the Base layer to select only that part of the selection which overlaps the Base layer , fill the selection on Gloss layer with any color.
14. Reduce the Fill Opacity of Gloss layer to 0% , go to its Blending options and set these values :


With the Gloss layer selected , Ctrl+Click on the Ring 4 layer and press Delete key.
Here is my result:

You can download the PSD file from here.
Hope you all like it
I am anxiously waiting for your results.