Not all fields have to be filled out. Just play around with it.
Image size (pixels):

Background color
R: G: B:

Foreground color
R: G: B:

Foreground fill transparency (1-10):

Min. shape size (1-200): Max. shape size (1-200):

Density (0-100):

Number of layers:

Shape type: Circles Ellipses Squares Rectangles Lines

View image tiled

Image size:Number of pixels across and down the image will be. 1-1000
Background color:In decimal. 0-255
Foreground color:In decimal. 0-255
Foreground fill Transparency:1 is no transparency and 10 is full transparency.
Shape size:The range of sizes the foreground shapes will be. Put them both the same for uniform size shapes.
Density:Number of circles on the image compared to its size
Number of layers:How many transitional layers, and hence the number of colors, between the foreground and background