Examine source code of Pikachu

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Pikachu",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.png"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "right center"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgba(22, 20, 20, 0)",
      "toolbar_text": "rgb(203, 49, 44)",
      "frame": "rgb(252, 219, 9)",
      "tab_background_text": "rgb(11, 11, 11)",
      "toolbar_field": "rgba(255, 255, 224, 0.44)",
      "toolbar_field_text": "rgb(0, 0, 0)",
      "tab_line": "rgb(247, 220, 106)",
      "popup": "rgb(252, 219, 9)",
      "popup_text": "rgb(8, 8, 8)",
      "tab_loading": "rgb(247, 220, 106)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{f86773d5-b91a-43fc-9311-5efa5f584919}"
    }
  }
}