How To Do
1. Create New Document with size 400 x 400px.Start by creating a circle thin frame using custom shape tool (U).
2. Select the inner side of the circle frame with direct selection tool ( A ).
3. Press Ctrl+T and scale down to the size of inner hole.
4. Create a multicolor gradient like shown in image below. Save by clicking "New" in gradient window.
5. Apply gradient overlay layer style to CD layer. Select the gradient you just saved in previous step and adjust other settings as shown.
6. Also apply stroke and drop shadow using following settings.
7. Create another circular frame shape and place over inner hole.
8. Apply layer styles as shown in following images.
9. Change opacity of this layer to 50%.