Examine source code of Huel Dark

{
  "name": "Huel Dark",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "BLANK_ICON.png"
    },
    "colors": {
      "frame": "rgba(11, 11, 11, 1)",
      "tab_background_text": "rgba(161, 161, 161, 1)",
      "toolbar": "rgba(22, 22, 22, 1)",
      "bookmark_text": "rgba(255, 255, 255, 1)",
      "toolbar_field": "rgba(36, 36, 36, 1)",
      "toolbar_field_text": "rgba(255, 255, 255, 1)",
      "tab_line": "rgba(24, 24, 24, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{cc8e6c10-e477-4c92-a517-149f7a2ff50c}"
    }
  }
}