i'm guessing 4 colours. different sizes. but in total, how many did you use?
132, plus I count the exterior rim of the whole arrangement = 133. deconstructing the piece I found that 44 don't count; they are black but I forgot to turn them out of sync, so they're all hidden under color circles. That leaves 88: 11 yellow, 11 blue, 33 red and 33 green. Plus the rim. Software: MacDraft PE, HP-generated Adobe pdf, Apple preview, Photoshop Elements 3 and Corel Painter Essentials 4 with some of the old preliminary work in Appleworks 6. Each has a little something that the others don't. I'd like to learn how to animate them: moving the circle groups over each other gives some spectacular effects.
it is almost tempting to say, guess the number of circles! XD