Examine source code of Bleu Ciel

{
  "name": "Bleu Ciel",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "mozilla theme header bleu ciel cfel.png"
    },
    "colors": {
      "frame": "rgba(229, 230, 232, 1)",
      "tab_background_text": "rgba(41, 0, 176, 1)",
      "toolbar_field_text": "rgba(41, 0, 176, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{81571615-5cfa-4d13-bbcb-839d21184938}"
    }
  }
}