Click to generate a shape. Move the sliders to change type of shape, color, saturation and brightness. Space to hide variables. There's a possibility you'll get a line. Backdrop and shapes are 100% pen. Shape 1 = Triangle. Shape 2 = Circle. Shape 3 = Square. Shape 4 = Random 4-sided shape. There are 3,240,000 possible combinations for the triangle. 9 for the circle. 70 for the square. There are more possibilities for the random 4-sided shape then I care to calculate. Whoops, accidental un-share.
I thought this one up during math class, so my teacher. Thanks to @Thedeziner for the thumbnail you should follow him. Music is Mozart.