Examine source code of Subtle Grey Look

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Grey Stone",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-037-b73f9b34467ba541de861f5b4c0c6316.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(122, 141, 168)",
      "toolbar_text": "rgb(8, 7, 6)",
      "frame": "rgb(125, 125, 125)",
      "tab_background_text": "rgb(8, 7, 6)",
      "toolbar_field": "rgb(138, 154, 178)",
      "toolbar_field_text": "rgb(8, 7, 6)",
      "tab_line": "rgb(8, 7, 6)",
      "popup": "rgb(138, 154, 178)",
      "popup_text": "rgb(8, 7, 6)",
      "tab_loading": "rgb(8, 7, 6)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{7f991f2b-114e-49d0-b986-ea3b7271d3cd}"
    }
  }
}