Examine source code of Github Dark

{
  "name": "Github Dark",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "none.png"
    },
    "colors": {
      "frame": "rgba(22, 27, 34, 1)",
      "tab_background_text": "rgba(139, 148, 158, 1)",
      "toolbar": "rgba(13, 17, 23, 1)",
      "bookmark_text": "rgba(139, 148, 158, 1)",
      "toolbar_field": "rgba(22, 27, 34, 1)",
      "toolbar_field_text": "rgba(88, 166, 255, 1)",
      "tab_line": "rgba(88, 166, 255, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{eb9bda18-038c-412c-847f-ceb785e90b76}"
    }
  }
}