R – How to set a style for a cell in datagrid

I have done some thing like that but in my case color was also coming from data also but it will help you. You have to override the Datagrid and override drawRowBackground method

public class CustomDataGrid extends AdvancedDataGrid
    {   

        protected override function drawRowBackground(s:Sprite, rowIndex:int, y:Number, height:Number, color:uint, dataIndex:int):void{
              var XMLdata:XML=rowNumberToData(dataIndex) as XML;               
              if(XMLdata!=null){          
                        if(XMLdata.attribute(Constants.col) != undefined && XMLdata.attribute(Constants.col) != ""){
                            color=XMLdata.attribute(Constants.col);         
                        }else{
                            color=0xFFFFFF;
                        }                            
              }               
              super.drawRowBackground(s,rowIndex,y,height,color,dataIndex);         
        }           
    }

By this you can get any data from the row and according to it give the color.

Bind the item renderer's data property (or set a listener) so that it disables the hyperlink when changed. The data property changes each time the cell receives new data to render.

Here are a couple possibilities.

class User {
  public var type:String;
}

<mx:Panel ...

  <mx:Component id="simple">
    <mx:Label styleName="{data.type}"></mx:Label>
  </mx:Component>

  <mx:Component id="userRenderer">
    <mx:Label dataChange="onChange(event)">
      <mx:Script>
        <![CDATA[
          private function onChange(event:FlexEvent) {
            // do something
          }
        ]]>
      </mx:Script>

    </mx:Label>
  </mx:Component>

  <mx:DataGrid ...>
    <mx:columns>
        <mx:DataGridColumn itemRenderer="userRenderer" />
    </mx:columns>
  </mx:DataGrid>
</mx:Panel>

With a minimal snippet of your code, the example might be more fitting, but you should be able to adapt this.