Examine source code of Cold dark

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Cold dark",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-000-5672c42860d5b06e1058dc477397f3ef.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(38, 38, 38)",
      "toolbar_text": "rgb(143, 116, 219)",
      "frame": "rgb(26, 26, 26)",
      "tab_background_text": "rgb(82, 139, 176)",
      "toolbar_field": "rgb(21, 21, 21)",
      "toolbar_field_text": "rgb(122, 116, 221)",
      "tab_line": "rgb(53, 15, 172)",
      "popup": "rgb(21, 21, 21)",
      "popup_text": "rgb(82, 139, 176)",
      "tab_loading": "rgb(53, 15, 172)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{64d45f6c-0da1-49bc-b4cc-dc351110aabc}"
    }
  }
}