Examine source code of Vikings_Ragnar

{
  "theme": {
    "images": {
      "theme_frame": "header.png"
    },
    "colors": {
      "frame": "#b5b5b5",
      "tab_background_text": "#bdbdbd"
    }
  },
  "version": "2.0",
  "name": "Vikings_Ragnar",
  "manifest_version": 2,
  "description": "Ragnar Lothbrok"
}