Examine source code of Hell City Devil Heads

{
  "theme": {
    "images": {
      "theme_frame": "Persona_Header3_devilheads.jpg"
    },
    "colors": {
      "frame": "#140303",
      "tab_background_text": "#f70d0d"
    }
  },
  "version": "2.0",
  "name": "Hell City Devil Heads",
  "manifest_version": 2,
  "description": "Hell City devil heads are sure to bring out the little devil in you."
}