如何在Google条形图中仅填充背景颜色的一半

Question

如何在Google条形图中仅填充背景色的一半。这是代码：

 this.columnChart2 = {  // use :any or :GoogleChartInterface
      chartType: 'ColumnChart',
      dataTable: this.convertPerformanceDataToGraph1(performanceData, 'UNIQUE CXs RESTORED'),
      //   dataTable:[ ['NE name', 'Unique CXs Restored','teamAverage'],
      //   ['ChandraShekhar', 22,0], ['Mayur SS', 18,0],
      //   ['Sathish k', 12,0], ['Suraj ks', 8,0],
      //   ['Manjunath', 7,0],
      //   ['Sumanth', 0,0],
      // ],

      options: {
        // type: "area",  
        // fillOpacity: .8,
        title: 'Performance: Unique CXs Restored',
        orientation: 'vertical',
        width: 900,
        height: 500,
        bar: { groupWidth: 8, groupHeight: '4px' },
        series: {
          0: { color: '#fff4ea' },
          1: { color: '#ff9930' }
        },
        legend: { position: 'bottom', alignment: 'end', symbolRadius: 2, maxWidth: 50 },
        xAxis: { gridDashType: 'dash' },
        indexLabel: '{Unique CXs Restored}',
        indexLabelPlacement: 'outside',
        indexLabelOrientation: 'horizontal',
        chartArea: {
          backgroundColor: {
             fill:'#fff4ea',
          }
        },

      },
   };