Examine source code of Raven Behind Chains

{
  "theme": {
    "images": {
      "theme_frame": "header.png"
    },
    "colors": {
      "frame": "#2f4761",
      "tab_background_text": "#e6fffd"
    }
  },
  "version": "2.0",
  "name": "Raven Behind Chains",
  "manifest_version": 2,
  "description": "A Raven put up as a theme with a friend in mind!"
}