Step one:
Open a new document and fill it with black. Select a circel and fill this with red. Choose "Select - Modify - Contract" and use 100 pixels or so, in order to get a smaller selection. Don't worry that it isn't a perfect circle, that doesn't matter. Fill this selection with yellow. Repeat "Select - Modify - Contract" and fill with white. Deselect. You will get a 'target circle' like in this screendump.

Step two:
Select "Filter - Brush Strokes - Spatter"

Step three:
Set the Spray Radius as high as possible (25 pixels) and the Smoothness low. 2 pixels will do fine.

Step four:
A nice result is already shown here. You can get a smoother result however, by adding a Radial Blur, using Zoom, Good Quality and an Amount of 100 pixels.

Step five:
The end result including a Radial Blur.