Examine source code of Monster Hunter Journal

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Monster Hunter Journal",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.jpg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "right top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgba(44, 29, 32, 0.57)",
      "toolbar_text": "rgb(255, 243, 231)",
      "frame": "rgb(62, 94, 83)",
      "tab_background_text": "rgb(255, 243, 231)",
      "toolbar_field": "rgb(62, 104, 87)",
      "toolbar_field_text": "rgb(255, 243, 231)",
      "tab_line": "rgb(249, 220, 196)",
      "popup": "rgb(53, 70, 63)",
      "popup_text": "rgb(247, 241, 224)",
      "button_background_active": "rgba(44, 92, 98, 0.63)",
      "button_background_hover": "rgba(80, 143, 119, 0.7)",
      "icons_attention": "rgb(255, 153, 34)",
      "ntp_background": "rgb(96, 79, 69)",
      "popup_border": "rgba(221, 192, 137, 0.59)",
      "popup_highlight": "rgb(63, 184, 148)",
      "tab_loading": "rgba(33, 255, 195, 0.77)",
      "tab_selected": "rgba(38, 86, 72, 0.8)",
      "toolbar_bottom_separator": "rgb(94, 35, 21)",
      "toolbar_field_border_focus": "rgb(89, 184, 141)",
      "toolbar_field_border": "rgba(18, 51, 35, 0.75)",
      "toolbar_field_highlight": "rgb(63, 184, 148)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{e118e921-56a4-4c24-996e-7ad42931bdfe}"
    }
  }
}