Examine source code of Steel Ingot

{
  "manifest_version": 2,
  "version": "1.2",
  "name": "Steel Ingot",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-000-5672c42860d5b06e1058dc477397f3ef.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(174, 174, 174)",
      "toolbar_text": "rgb(0, 0, 0)",
      "frame": "rgb(90, 90, 90)",
      "tab_background_text": "rgb(221, 221, 221)",
      "toolbar_field": "rgba(230, 230, 230, 0.75)",
      "toolbar_field_text": "rgb(66, 140, 24)",
      "tab_line": "rgb(111, 111, 111)",
      "popup": "rgb(206, 206, 206)",
      "popup_text": "rgb(26, 26, 26)",
      "icons": "rgb(75, 75, 75)",
      "toolbar_field_border": "rgb(154, 154, 154)",
      "toolbar_top_separator": "rgb(174, 174, 174)",
      "toolbar_vertical_separator": "rgb(112, 112, 112)",
      "tab_loading": "rgb(111, 111, 111)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{772b64cb-ad63-44d4-936d-afa23f1fcd54}"
    }
  }
}