Unable to fill background color

Why does this code have no effect?It can not fill the background color?Who can help me？

` json.map((v, i) => { if(maxLen<Object.keys(v).length){ maxLen=Object.keys(v).length; } return Object.keys(v).map((k, j) => { //取出键对应的值

        return Object.assign({}, { //拼接输出的sheet
          v: v[k],
          position: (j > 25 ? this.getCharCol(j) : String.fromCharCode(65 + j)) + (i + 1),
           
        })}
      )
    }).reduce((prev, next) =>  prev.concat(next)).forEach(function (v) {
      var cell={ //转换输出json
        v: v.v,
        s:{ 
          fill : {
            fgColor : {
                theme : 8,
                tint : 0.3999755851924192,
                rgb : '08CB26'
            }
          },
          font : {
              color : {
                  rgb : "FFFFFF"
              },
              bold : true
          },
          border : {
              bottom : {
                  style : "thin",
                  color : {
                      theme : 5,
                      tint : "-0.3",
                      rgb: "E8E5E4"
                  }
              }
          }  
        }
      }
      if ( typeof cell.v === 'number')  
           cell.t = 'n';  
        else if ( typeof cell.v === 'boolean')  
            cell.t = 'b';  
        else if (cell.v instanceof Date) {  
            cell.t = 'n';  
            cell.z = XLSX.SSF._table[14];  
            cell.v = datenum(cell.v);  
        } else  
            cell.t = 's';
      tmpdata[v.position] = cell;
      
    })

`

[SheetJSDev]

We offer this in the Pro compendium. Since companies have paid for the features already, it would be unfair to them if we turned around and made it available as open source. We have a longer comment in a gist.

[JesusFregoso]

Sorry my bad im using this fork https://github.com/xSirrioNx/js-xlsx i think is better the should merge to master