Examine source code of Blackbird Theme (Dark)

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Blackbird Theme (Dark)",
  "description": "A custom dark theme inspired by Blackbird theme by Nick C, now on Firefox.",
  "author": "dxdroni",
  "applications": {
    "gecko": {
      "id": "dxdroni@dronidev.pl",
      "strict_min_version": "58.0"
    }
  },
  "theme": {
    "colors": {
      "frame": "#0A1929",
      "tab_background_text": "#B2BAC2",
      "tab_text": "#FFFFFF",
      "tab_line": "#0A1929",
      "tab_selected": "#132F4C",
      "toolbar": "#0A1929",
      "toolbar_text": "#FFFFFF",
      "toolbar_field": "#0C1F33",
      "toolbar_field_text": "#FFFFFF",
      "toolbar_field_border": "#0A1929",
      "toolbar_field_focus": "#0A1929",
      "toolbar_top_separator": "#0A1929",
      "toolbar_vertical_separator": "#0A1929",
      "toolbar_bottom_separator": "#0A1929",
      "bookmark_text": "#FFFFFF",
      "button_background_hover": "#1E4976",
      "button_background_active": "#173A5E",
      "popup": "#0A1929",
      "popup_text": "#FFFFFF",
      "popup_border": "#1E4976",
      "popup_highlight": "#173A5E",
      "popup_highlight_text": "#FFFFFF",
      "ntp_background": "#0A1929",
      "ntp_text": "#FFFFFF",
      "sidebar": "#0A1929",
      "sidebar_text": "#FFFFFF",
      "sidebar_highlight": "#173A5E",
      "sidebar_highlight_text": "#FFFFFF"
    },
    "properties": {
      "color_scheme": "dark"
    }
  }
}