Examine source code of heart wings

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "heart wings",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.png"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "right center"
      ],
      "additional_backgrounds_tiling": [
        "no-repeat"
      ]
    },
    "colors": {
      "toolbar": "rgba(255, 255, 255, 0)",
      "toolbar_text": "rgb(0, 0, 0)",
      "frame": "rgb(174, 174, 174)",
      "tab_background_text": "rgb(115, 115, 115)",
      "toolbar_field": "rgba(255, 250, 253, 0.52)",
      "toolbar_field_text": "rgb(0, 0, 0)",
      "tab_line": "rgb(255, 209, 235)",
      "popup": "rgb(174, 174, 174)",
      "popup_text": "rgb(255, 235, 247)",
      "button_background_active": "rgb(255, 255, 255)",
      "icons": "rgb(255, 209, 235)",
      "popup_border": "rgb(255, 235, 247)",
      "sidebar_border": "rgb(255, 235, 247)",
      "sidebar_text": "rgb(255, 235, 247)",
      "sidebar": "rgb(174, 174, 174)",
      "tab_selected": "rgb(255, 235, 247)",
      "tab_text": "rgb(0, 0, 0)",
      "toolbar_bottom_separator": "rgb(255, 235, 247)",
      "toolbar_field_border": "rgb(255, 235, 247)",
      "toolbar_top_separator": "rgba(255, 0, 0, 0)",
      "tab_loading": "rgb(255, 209, 235)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{975b5128-244c-4079-a659-c0d4fba895aa}"
    }
  }
}