Examine source code of Outlining

{
  "theme": {
    "images": {
      "theme_frame": "p3large.png"
    },
    "colors": {
      "frame": "#ffffff",
      "tab_background_text": "#ffffff"
    }
  },
  "version": "2.0",
  "name": "Outlining",
  "manifest_version": 2,
  "description": "Just outlines and underlines stuff at the top... mainly designed for me but should work for others if you pin four 'app tabs'"
}