Examine source code of Simple monochrome theme

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Simple monochrome theme",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-000-5672c42860d5b06e1058dc477397f3ef.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(43, 43, 43)",
      "toolbar_text": "rgb(238, 238, 238)",
      "frame": "rgb(26, 26, 26)",
      "tab_background_text": "rgb(204, 204, 204)",
      "toolbar_field": "rgb(60, 60, 60)",
      "toolbar_field_text": "rgb(238, 238, 238)",
      "tab_line": "rgb(238, 238, 238)",
      "popup": "rgb(43, 43, 43)",
      "popup_text": "rgb(238, 238, 238)",
      "icons": "rgb(238, 238, 238)",
      "tab_selected": "rgb(59, 59, 59)",
      "tab_text": "rgb(255, 255, 255)",
      "tab_loading": "rgb(238, 238, 238)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{fff98d6d-7019-4869-bda2-5cc83ab58f7a}"
    }
  }
}