QAbstractTableModel , custom data

i am trying to color a particular column in AbstractTableModel. But I wonder why its not working.........Here is the code snipp....
thanks.

Code:

---

function ColorModel(parent)
{
QAbstractTableModel.call(this, parent);  
}
ColorModel.prototype= new QAbstractTableModel();
 
ColorModel.prototype.rowCount= function (QModelIndex)
{
    return 2;
}
 
ColorModel.prototype.columnCount= function (QModelIndex)
{
    return 5;
}
ColorModel.prototype.color=function(){
	return new QColor(127, 200 , 24);
}
ColorModel.prototype.data = function(index, role)
{		
	var dataR;
	if (role == Qt.DisplayRole) {
            return 5;
        } 
	if (role == Qt.BackgroundRole) {	
		if (index.column() == 1)	
		        //return new QColor(127, 200 , 24);
			return this.color;
			//var color = new RGBColor('darkblue');
        } 
 
        return dataR;
}

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