Examine source code of middleofbelly

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "uhh",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.png",
        "images/1.png",
        "images/2.png"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "right center",
        "left center",
        "center center"
      ],
      "additional_backgrounds_tiling": [
        "no-repeat",
        "no-repeat",
        "no-repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(179, 66, 66)",
      "toolbar_text": "rgb(68, 71, 179)",
      "frame": "rgb(133, 80, 166)",
      "tab_background_text": "rgb(255, 255, 255)",
      "toolbar_field": "rgb(255, 255, 255)",
      "toolbar_field_text": "rgb(123, 127, 204)",
      "tab_line": "rgb(179, 44, 71)",
      "popup": "rgb(238, 79, 79)",
      "popup_text": "rgb(0, 11, 255)",
      "tab_loading": "rgb(179, 44, 71)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{f59c78cc-ce22-4d6e-86d0-aa3448d74bb6}"
    }
  }
}