Examine source code of Blue Insomnia-Test

{
  "name": "Blue Insomnia-Test",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "Firefox background.png"
    },
    "colors": {
      "frame": "rgba(3, 3, 3, 1)",
      "tab_background_text": "rgba(3, 3, 3, 1)",
      "toolbar": "rgba(0, 0, 0, 0.4)",
      "bookmark_text": "rgba(255, 255, 255, 1)",
      "toolbar_field": "rgba(0, 0, 0, 0.23)",
      "toolbar_field_text": "rgba(255, 255, 255, 1)",
      "tab_line": "rgba(0, 0, 0, 0)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{d188decc-b7bd-46a7-8595-3517714e88e5}"
    }
  }
}