Examine source code of Gentle Night

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Gentle Night",
  "theme": {
    "images": {},
    "properties": {},
    "colors": {
      "toolbar": "rgb(35, 34, 37)",
      "toolbar_text": "rgb(180, 180, 180)",
      "frame": "rgb(35, 34, 37)",
      "tab_background_text": "rgb(180, 180, 180)",
      "toolbar_field": "rgb(28, 27, 30)",
      "toolbar_field_text": "rgb(200, 200, 200)",
      "tab_line": "rgba(57, 56, 60, 0)",
      "popup": "rgb(47, 46, 50)",
      "popup_text": "rgb(180, 180, 180)",
      "button_background_active": "rgb(47, 46, 50)",
      "button_background_hover": "rgb(47, 46, 50)",
      "frame_inactive": "rgb(35, 34, 37)",
      "icons_attention": "rgb(0, 186, 255)",
      "icons": "rgb(180, 180, 180)",
      "ntp_background": "rgb(35, 34, 37)",
      "ntp_text": "rgb(180, 180, 180)",
      "popup_border": "rgb(28, 27, 30)",
      "popup_highlight_text": "rgb(240, 240, 240)",
      "popup_highlight": "rgb(47, 46, 50)",
      "sidebar_border": "rgb(28, 27, 30)",
      "sidebar_highlight_text": "rgb(240, 240, 240)",
      "sidebar_highlight": "rgb(57, 56, 60)",
      "sidebar_text": "rgb(200, 200, 200)",
      "sidebar": "rgb(47, 46, 50)",
      "tab_background_separator": "rgba(35, 34, 37, 0)",
      "tab_loading": "rgb(0, 186, 255)",
      "tab_selected": "rgb(57, 56, 60)",
      "tab_text": "rgb(180, 180, 180)",
      "toolbar_bottom_separator": "rgba(35, 34, 37, 0)",
      "toolbar_field_border_focus": "rgba(28, 27, 30, 0)",
      "toolbar_field_border": "rgba(28, 27, 30, 0)",
      "toolbar_field_focus": "rgba(28, 27, 30, 0)",
      "toolbar_field_highlight_text": "rgb(0, 0, 0)",
      "toolbar_field_highlight": "rgba(255, 255, 255, 0.4)",
      "toolbar_field_separator": "rgba(35, 34, 37, 0)",
      "toolbar_field_text_focus": "rgba(28, 27, 30, 0)",
      "toolbar_top_separator": "rgba(35, 34, 37, 0)",
      "toolbar_vertical_separator": "rgba(35, 34, 37, 0)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{6111860e-f40a-45ef-a0e5-a5ed67fb0cb5}"
    }
  }
}