Steps to create Radial Gradient

• Create a new file with the required size.

         

• Select the lightest color of the needed gradient as primary color and darkest as the secondary color.
• Go to  CarpeTools>>Create>>Gradient.

         

• Add a new layer, create a gradient effect with the same type and check the box for shades of the graph.

         

• Using a color tool, separate all the colors into layers.
• Delete the gradient with a shades layer.
• Select the first color from the color layer and copy the selected area from the created gradient and paste it on the color layer.
•  Now, Replicate >>All over and repeat the selected area all over.
• Repeat the process for all colors.
• Create a new layer and select a full circle.

         

• Go to CarpeTool to create the selection gradient with 8 steps and size of approximately 395.

• Select the corner color of the circle as shown in the picture below, go to the lightest shade of the gradient and click Ctrl+I to deselect the area and press delete.
• Repeat the process simultaneously (going from end to the center of the circle) to create a Radial gradient effect with four colors.

     

• Here's the final result in visualization.