Making Rainbow Swirls

Step 1
Open up a blank picture in Photofiltre and using the Selection Tool make whatever sized squares you want and fill them with colors so that they end up looking like this:


Step 2
Now select the entire color block and move the selection on each of the four sides so that it's a little bigger than the original selection.


Step 3
Now go to Filter >> Deform >> Twirl and set your settings as mine:

Repeat this as many times as you want until you feel like it looks like a swirl/circle.