Examine source code of Slate theme for Firefox

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Version 2",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-000-5672c42860d5b06e1058dc477397f3ef.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(26, 53, 91)",
      "toolbar_text": "rgb(237, 243, 251)",
      "frame": "rgb(9, 26, 50)",
      "tab_background_text": "rgb(255, 255, 255)",
      "toolbar_field": "rgb(32, 33, 37)",
      "toolbar_field_text": "rgb(255, 255, 255)",
      "tab_line": "rgb(5, 30, 56)",
      "popup": "rgb(32, 33, 37)",
      "popup_text": "rgb(255, 255, 255)",
      "tab_selected": "rgb(46, 53, 86)",
      "toolbar_field_border_focus": "rgb(138, 180, 248)",
      "toolbar_field_focus": "rgb(32, 33, 36)",
      "toolbar_field_highlight": "rgb(83, 102, 133)",
      "tab_loading": "rgb(5, 30, 56)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{c3afcd11-ed88-40ee-8639-8d6106dc4d4c}"
    }
  }
}