Examine source code of cozy 70's

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "cozy 70's",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-021-775b159da029a74f5c76e835cd65e9dc.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(214, 116, 43)",
      "toolbar_text": "rgb(67, 30, 21)",
      "frame": "rgb(128, 176, 164)",
      "tab_background_text": "rgb(255, 231, 189)",
      "toolbar_field": "rgb(255, 231, 189)",
      "toolbar_field_text": "rgb(208, 79, 44)",
      "tab_line": "rgb(217, 172, 54)",
      "popup": "rgb(255, 231, 189)",
      "popup_text": "rgb(67, 30, 21)",
      "tab_loading": "rgb(217, 172, 54)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{5807be04-e8dd-4f50-9a1b-ff19e455d448}"
    }
  }
}