Examine source code of Chainsawman

{
  "name": "Chainsawman",
  "manifest_version": 2,
  "version": "2.0",
  "theme": {
    "images": {
      "theme_frame": "undefined - Imgur.gif"
    },
    "colors": {
      "frame": "rgba(0, 0, 0, 1)",
      "tab_background_text": "rgba(237, 237, 237, 1)",
      "toolbar": "rgba(144, 147, 168, 0.14)",
      "bookmark_text": "rgba(237, 237, 237, 1)",
      "toolbar_field": "rgba(23, 25, 28, 0.4)",
      "toolbar_field_text": "rgba(237, 237, 237, 1)",
      "tab_line": "rgba(19, 20, 38, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{335eb68f-2578-45a0-9215-bf6965c1ffd9}"
    }
  }
}