colours in grid

Here my scenario is I want to highlight the records in grid if the customer group of the particular record is 30.

• Inorder to achieve that I have created a form with CustTable as datasource for that form .

• In design node i have created a grid with fields CustGroup, Currency, Salesgroup and AccountNum. 

•  Now I have overridden the displayoption method() in form datasource methods.

         public void displayOption(CustTable _CustTable, FormRowDisplayOption _options)
        {
         int myColor=WinApi::RGB2int(50,255,50);
         ;

        //if(_CustTable.CreditMax <= 100100)
        if(_CustTable.CustGroup == "30")
        _options.backColor(myColor);

        super(_CustTable, _options);
         //CustTable_ds.research();
         }
      The final form shoulde be