You can change the size, angle of rotation, colors and the line width using the buttons under "Show Options". Change the value and then click on the button. If you want to see a different pattern with the same settings you can click on the Size/Redo button without changing the size.
You can also hide/see this text using the "Toggle Text" button and you can refresh from the server using the refresh button.
Size is basically the maximum radius in pixels. Clicking on the size button again will give you another pattern at the same size. You can use any values for the angle of rotation in degrees, but numbers that evenly divide into 360 work best. The colors can be given in common words or in hexidecimals like #aaffaa where the first two values are for red and next two are for green and the last two are for blue. These can have values 0-9 and a-f. #000000 would be black and #ffffff would be white. The Line Width designates the width of the line in pixels.