Shift-Click the flag. Doesn't really do much though. Press "C" to show and hide the amount of circles generated. Adjust the gapsize% variable to set how big the circle should be once the maximum radius has been found. I suggest a percentage below 25%, but you do what you want. You cannot change it once it has started generating, so change it and then click the green flag again to generate.
Uses math instead of <touching_colour_?> blocks to detect the closest circle. A lot more accurate(and faster), as trial and error are not needed. uh, thanks for the circle art project by @MrRubikxSC Really seems to have problems working in phosp
