Examine source code of eevee & flareon

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "eevee & flareon",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.png"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "right center"
      ],
      "additional_backgrounds_tiling": [
        "no-repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(236, 220, 249)",
      "toolbar_text": "rgb(0, 0, 0)",
      "frame": "rgb(252, 248, 211)",
      "tab_background_text": "rgb(0, 0, 0)",
      "toolbar_field": "rgba(0, 0, 0, 0)",
      "toolbar_field_text": "rgb(0, 0, 0)",
      "tab_line": "rgb(253, 124, 73)",
      "popup": "rgb(236, 220, 249)",
      "popup_text": "rgb(0, 0, 0)",
      "tab_loading": "rgb(253, 124, 73)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{33551719-9309-4e77-a40f-d9b03e34b123}"
    }
  }
}