Change Background Datatable Transparent

Webix JS
#1

Hello,
Anyone can help me about how to change background (yellow color) in datatable to transparent and show background image in css “mystyle”?
I Have this sample
https://snippet.webix.com/a98i230p

Thank you

#2

try to replace

  .custom .webix_column{
  	background-color:yellow;
  }

with

    .custom {
        background:transparent;
    }