Examine source code of F1 dark theme

{
  "manifest_version": 2,
  "version": "3.0",
  "name": "F1 dark theme updated",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.png"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "right top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(44, 39, 39)",
      "toolbar_text": "rgb(255, 0, 0)",
      "frame": "rgb(255, 0, 0)",
      "tab_background_text": "rgb(184, 0, 0)",
      "toolbar_field": "rgb(57, 57, 57)",
      "toolbar_field_text": "rgb(255, 0, 0)",
      "tab_line": "rgb(255, 0, 0)",
      "popup": "rgb(44, 39, 39)",
      "popup_text": "rgb(255, 0, 0)",
      "tab_selected": "rgb(68, 3, 3)",
      "tab_loading": "rgb(255, 0, 0)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{fc7efb53-cd8f-4325-ac03-af6ba78a2d8a}"
    }
  }
}