Examine source code of GitHub - Dark Dimmed

{
  "name" : "GitHub - Dark Dimmed",
  "manifest_version" : 2 ,
  "version" : "1.0",
  "theme": {
    "images": {
      "theme_frame": "emEE0a0D225dDf762f.png"
    },
    "colors": {
      "frame": "rgba(34, 39, 46, 1)",
      "tab_background_text": "rgba(229, 233, 240, 1)",
      "toolbar": "rgba(48, 54, 61, 1)",
      "bookmark_text": "rgba(236, 239, 244, 1)",
      "toolbar_field": "rgba(45, 51, 57, 1)",
      "toolbar_field_text": "rgba(236, 239, 244, 1)"
    }
  }
}