Examine source code of osakadark

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "OsakaDark",
  "theme": {
    "images": {},
    "properties": {},
    "colors": {
      "toolbar": "rgb(28, 28, 38)",
      "toolbar_text": "rgb(161, 164, 206)",
      "frame": "rgb(17, 17, 23)",
      "tab_background_text": "rgb(161, 164, 206)",
      "toolbar_field": "rgb(28, 28, 38)",
      "toolbar_field_text": "rgb(161, 164, 206)",
      "tab_line": "rgb(238, 109, 133)",
      "popup": "rgb(28, 28, 38)",
      "popup_text": "rgb(161, 164, 206)",
      "icons_attention": "rgb(238, 109, 133)",
      "icons": "rgb(161, 164, 206)",
      "ntp_background": "rgb(17, 17, 23)",
      "ntp_text": "rgb(161, 164, 206)",
      "popup_border": "rgba(17, 17, 23, 0)",
      "popup_highlight_text": "rgb(161, 164, 206)",
      "popup_highlight": "rgba(238, 109, 133, 0.6)",
      "sidebar_border": "rgba(238, 109, 133, 0)",
      "sidebar_highlight_text": "rgb(161, 164, 206)",
      "sidebar_highlight": "rgb(238, 109, 133)",
      "sidebar_text": "rgb(161, 164, 206)",
      "sidebar": "rgb(28, 28, 38)",
      "tab_background_separator": "rgb(28, 28, 38)",
      "tab_loading": "rgb(238, 109, 133)",
      "tab_selected": "rgb(28, 28, 38)",
      "tab_text": "rgb(238, 109, 133)",
      "toolbar_bottom_separator": "rgba(28, 28, 38, 0)",
      "toolbar_field_border_focus": "rgba(28, 28, 38, 0)",
      "toolbar_field_border": "rgba(28, 28, 38, 0)",
      "toolbar_field_focus": "rgb(28, 28, 38)",
      "toolbar_field_highlight_text": "rgb(161, 164, 206)",
      "toolbar_field_highlight": "rgba(238, 109, 133, 0.6)",
      "toolbar_field_separator": "rgba(238, 109, 133, 0)",
      "toolbar_field_text_focus": "rgb(161, 164, 206)",
      "toolbar_top_separator": "rgba(238, 109, 133, 0)",
      "toolbar_vertical_separator": "rgba(161, 164, 206, 0)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{f06138f3-b2bb-4498-8e67-7f003238c708}"
    }
  }
}