Define the number of fringe colors, drawing thickened elements (red color gradient).Default value is 1.Thinner Color #:Define the number of fringe colors, drawing thinned elements (blue color gradient).Default value is 1.Zero Level Range:Define the range of values, within which, thickness variation can be ignored.For example a range of ±0.1, must be defined as the absolute difference i.e. 0.2.