Color utility structure.
        /// <summary>
        ///   Creates highlighted <c>PieSlice</c> object.
        /// </summary>
        /// <param name="boundingRectLeft">
        ///   x-coordinate of the upper-left corner of the rectangle that is
        ///   used to draw the top surface of the slice.
        /// </param>
        /// <param name="boundingRectTop">
        ///   y-coordinate of the upper-left corner of the rectangle that is
        ///   used to draw the top surface of the slice.
        /// </param>
        /// <param name="boundingRectWidth">
        ///   Width of the rectangle that is used to draw the top surface of
        ///   the slice.
        /// </param>
        /// <param name="boundingRectHeight">
        ///   Height of the rectangle that is used to draw the top surface of
        ///   the slice.
        /// </param>
        /// <param name="sliceHeight">
        ///   Slice height.
        /// </param>
        /// <param name="startAngle">
        ///   Starting angle.
        /// </param>
        /// <param name="sweepAngle">
        ///   Sweep angle.
        /// </param>
        /// <param name="color">
        ///   Color used for slice rendering.
        /// </param>
        /// <param name="shadowStyle">
        ///   Shadow style used for slice rendering.
        /// </param>
        /// <param name="edgeColorType">
        ///   Edge lines color type.
        /// </param>
        /// <param name="edgeLineWidth">
        ///   Edge lines width.
        /// </param>
        /// <returns>
        ///   <c>PieSlice</c> object with given values.
        /// </returns>
        protected virtual PieSlice CreatePieSliceHighlighted(float boundingRectLeft, float boundingRectTop, float boundingRectWidth, float boundingRectHeight, float sliceHeight, float startAngle, float sweepAngle, Color color, ShadowStyle shadowStyle, EdgeColorType edgeColorType, float edgeLineWidth)
        {
            Color highLightedColor = ColorUtil.CreateColorWithCorrectedLightness(color, ColorUtil.BrightnessEnhancementFactor1);

            return(new PieSlice(boundingRectLeft, boundingRectTop, boundingRectWidth, boundingRectHeight, sliceHeight, (float)(startAngle % 360), sweepAngle, highLightedColor, shadowStyle, edgeColorType, edgeLineWidth));
        }