The Exponential Smoothing coloring algorithm creates smoothly colored outside areas. It works well for both convergent and divergent fractal types, which means that it can be combined with almost any fractal formula.
Fractal formulas like Mandelbrot, Julia, and Phoenix have only divergent orbits, while types like Newton and Nova have only convergent orbits. The Magnet fractal formulas have both divergent and convergent orbits.
With the Color Divergent and Color Convergent parameters, you can enable coloring for divergent and convergent orbits. You should always enable at least one option. The formula runs slightly faster if you just enable the necessary options (only Magnet-like fractals require both parameters to be enabled).
The Divergent Density parameter can be used to tweak the color density for divergent parts of a fractal. It is only useful when both divergent and convergent orbits exist in the fractal.
Exponential Smoothing is available as a coloring algorithm in Standard.ucl and as a coloring plug-in in Standard.ulb.