You can't easily do this because in Ultra Fractal, each pixel is calculated as a separate, stand-alone entity that isn't influenced by the rest of the image. This for example allows the image to be subdivided for parallel calculations with multi-core processors and even networked computers.

Your proposed coloring algorithm would possibly change the coloring if you zoom in and frame a different portion of the fractal, with a different minimum iterations value. That would be pretty weird.

However, if you really want to, you can put all of the formula and coloring code in the global section of the coloring algorithm, and store information per pixel in a 2D array equal to the size of the image. You can now determine the minimum iteration count and color based on that. See this help topic to get started: http://www.ultrafractal.com/help/writing/formulas/globalsections.html

You can't easily do this because in Ultra Fractal, each pixel is calculated as a separate, stand-alone entity that isn't influenced by the rest of the image. This for example allows the image to be subdivided for parallel calculations with multi-core processors and even networked computers.
Your proposed coloring algorithm would possibly change the coloring if you zoom in and frame a different portion of the fractal, with a different minimum iterations value. That would be pretty weird.
However, if you really want to, you can put all of the formula and coloring code in the global section of the coloring algorithm, and store information per pixel in a 2D array equal to the size of the image. You can now determine the minimum iteration count and color based on that. See this help topic to get started: http://www.ultrafractal.com/help/writing/formulas/globalsections.html