Examine source code of Material (Dark)

{
  "manifest_version": 2,
  "name": "Material (Dark)",
  "version": "2.0",
  "description": "Provides a dark Material color palette to accompany the MaterialFox userChrome.css theme.",
  "homepage_url": "https://github.com/muckSponge/MaterialFox",
  "browser_specific_settings": {
    "gecko": {
      "id": "material-dark@mucksponge"
    }
  },
  "theme": {
    "colors": {
      "icons": "#f2f3f3",
      "icons_attention": "#5086ec",
      "button_background_hover": "#434649",
      "button_background_active": "#4e5153",
      "toolbar": "#333639",
      "toolbar_bottom_separator": "#282828",
      "popup": "#373737",
      "popup_border": "#555555",
      "popup_text": "#fff",
      "popup_highlight": "#0056d9",
      "popup_highlight_text": "#fff",
      "sidebar": "#333639",
      "sidebar_text": "#f1f3ee",
      "frame": "#202124",
      "tab_background_text": "#9ba0a5",
      "bookmark_text": "#f1f3ee"
    }
  }
}