SharePoint 2013 on-prem conditional formatting row by dueDate

Question

I would like to change the backgroundColor(row) of items based on DueDate on a Task list.

Answer 1

You can use Client Side Rendering (CSR) which represents a rendering engine for list views, list forms and search results.

See my answers given below:

1. How to color code a SharePoint list date field based on comparison with todays date?

2. How to Highlight a Row on Active Status

Answer 2

As Ganesh's suggestion, I modified code as below based on your requirement:

<script type="text/javascript">  
SP.SOD.executeFunc("clienttemplates.js", "SPClientTemplates", function() { 

  SPClientTemplates.TemplateManager.RegisterTemplateOverrides({
    OnPostRender: function (ctx) {
    var rows = ctx.ListData.Row;  
    for (var i = 0; i < rows.length; i++) {  
        var dueDate =new Date(rows[i]["DueDate"]); 
        var now = new Date(); 
        var rowId = GenerateIIDForListItem(ctx, rows[i]);
        var row = document.getElementById(rowId);
      // if there's no due date don't render anything
    if (dueDate == 'undefined' || !dueDate) {
        return '';
    }
    else if (dueDate < now) {
        row.style.backgroundColor ='red'  ;
    }
    else if(now-dueDate<=2) {
      row.style.backgroundColor ='yellow';
    }
    }   
    }
  });
});
</script>