How to set the editor's background and overwrite the background image

val editorFactory = EditorFactory.getInstance()
val document = editorFactory.createDocument("abc...")
val editor = editorFactory.createViewer(document).apply {
  backgroundColor = Color.RED
  component.preferredSize= Dimension(300, 200)
}

JBPopupFactory.getInstance().createDialogBalloonBuilder(editor.component, null)
  ...

How to disable the editor' background image in Popup?