Examine source code of Tormented demon

{
  "theme": {
    "images": {
      "theme_frame": "persona_header.jpg"
    },
    "colors": {
      "frame": "#1c1b1b",
      "tab_background_text": "#2e2e2e"
    }
  },
  "version": "2.0",
  "name": "Tormented demon",
  "manifest_version": 2,
  "description": "Fitting jagex's tormented demon wallpaper (at least on a 1920x1080 monitor)"
}