Examine source code of Dark Grey

{
  "name": "Dark Grey",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "Screenshot 2022-11-25 183229.png"
    },
    "colors": {
      "frame": "rgba(54, 54, 54, 1)",
      "tab_background_text": "rgba(168, 168, 168, 1)",
      "toolbar": "rgba(0, 0, 0, 1)",
      "bookmark_text": "rgba(255, 255, 255, 1)",
      "toolbar_field": "rgba(18, 18, 18, 1)",
      "toolbar_field_text": "rgba(112, 112, 112, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{a579790e-cc92-4cee-b911-772fe48be2bf}"
    }
  }
}