Examine source code of Colorful robik blocks

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Colorful robik blocks",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.png",
        "images/1.png"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "right top",
        "left bottom"
      ],
      "additional_backgrounds_tiling": [
        "no-repeat",
        "no-repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(212, 212, 160)",
      "toolbar_text": "rgb(245, 4, 54)",
      "frame": "rgb(204, 255, 154)",
      "tab_background_text": "rgb(244, 249, 245)",
      "toolbar_field": "rgb(215, 240, 40)",
      "toolbar_field_text": "rgb(42, 51, 237)",
      "tab_line": "rgb(249, 0, 51)",
      "popup": "rgb(234, 227, 228)",
      "popup_text": "rgb(38, 40, 81)",
      "tab_loading": "rgb(249, 0, 51)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{d6438178-7cc7-4c24-988f-683baa0ef4be}"
    }
  }
}