Examine source code of RedLineV3

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "RedLineV3",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-016-af8c49de75012ca2c007f953ff2e4499.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(26, 26, 26)",
      "toolbar_text": "rgb(255, 237, 237)",
      "frame": "rgb(3, 2, 2)",
      "tab_background_text": "rgb(165, 165, 165)",
      "toolbar_field": "rgb(0, 0, 0)",
      "toolbar_field_text": "rgb(244, 240, 224)",
      "tab_line": "rgb(173, 0, 3)",
      "popup": "rgb(26, 26, 26)",
      "popup_text": "rgb(255, 237, 237)",
      "icons": "rgb(206, 2, 2)",
      "popup_border": "rgb(173, 0, 3)",
      "tab_loading": "rgb(173, 0, 3)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{b4bfed1f-abb7-4223-993d-2ece9ed85e4c}"
    }
  }
}