Examine source code of purple grid

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "purple grid",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-005-f5f3cf677b1f132c75ddc7bd319dd1fc.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(195, 163, 203)",
      "toolbar_text": "rgb(255, 255, 255)",
      "frame": "rgb(170, 145, 175)",
      "tab_background_text": "rgb(239, 239, 239)",
      "toolbar_field": "rgb(225, 205, 230)",
      "toolbar_field_text": "rgb(250, 250, 250)",
      "tab_line": "rgb(252, 252, 252)",
      "popup": "rgb(206, 189, 212)",
      "popup_text": "rgb(255, 255, 255)",
      "tab_loading": "rgb(252, 252, 252)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{11c94808-e415-4e30-9a1d-93bc8e70f53e}"
    }
  }
}