Examine source code of Puzzling Bars

{
  "theme": {
    "images": {
      "theme_frame": "Puzzlg-Header.jpg"
    },
    "colors": {
      "frame": "rgba(229,230,232,1)",
      "tab_background_text": "#a6d3ff"
    }
  },
  "version": "2.0",
  "name": "Puzzling Bars",
  "manifest_version": 2,
  "description": "A nice puzzle look."
}