Examine source code of Indigo Red&Black

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Indigo red&black",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-016-af8c49de75012ca2c007f953ff2e4499.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(0, 0, 0)",
      "toolbar_text": "rgb(255, 255, 255)",
      "frame": "rgb(97, 94, 96)",
      "tab_background_text": "rgb(215, 226, 239)",
      "toolbar_field": "rgb(28, 29, 34)",
      "toolbar_field_text": "rgb(255, 255, 255)",
      "tab_line": "rgb(253, 7, 7)",
      "popup": "rgb(28, 28, 36)",
      "popup_text": "rgb(215, 226, 239)",
      "tab_loading": "rgb(253, 7, 7)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{6f00ec54-afc0-442e-8a08-b44ff55dd10d}"
    }
  }
}