anchor.diff:  
     static final List<Color> defaultColors = colorRange(
         new HslColor(1, 80, 70),
  -      new HslColor(360 * 10, 100, 0),
  +      new HslColor(360 * 20, 100, 0),
         1000);
   
     static _makeCssColors(List<Color> input) =>
         input.map((c) => c.toCss()).toList()..add("#000");
   }
   
  -const period2RadiusSquared = (1/16)*(1/16);
  +const period2RadiusSquared = (1/16);
   
   /// Calculates the value of the Mandelbrot image at one point.
   ///
  
positive.code:     }
      num nextA = aSquared - bSquared + x;
      num nextB = 2.0 * a * b + y;
      if (a == nextA && b == nextB) {
        return maxIterations; // fixed point found
      }
      a = nextA;
      b = nextB;
    }
  
    // didn't escape
  
negative.code:   double a = 0.0;
    double b = 0.0;
  
    // cycle detection: follow the same path but at half speed
    double pastA = 0.0;
    double pastB = 0.0;
  
    for (int count = 0; count < maxIterations; count++) {
      num aSquared = a * a;
      num bSquared = b * b;
  