Examine source code of Tricolour_India

{
  "theme": {
    "images": {
      "theme_frame": "header.png"
    },
    "colors": {
      "frame": "#cccccc",
      "tab_background_text": "#000000"
    }
  },
  "version": "2.0",
  "name": "Tricolour_India",
  "manifest_version": 2,
  "description": "Use bookmarks toolbar then it looks nice:-\nuse display your bookmarks tab to view bookmarks toolbars, this tab is in the upper corner of your right hand side"
}