Examine source code of NEL

{
  "name": "NEL",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "19827.jpg"
    },
    "colors": {
      "frame": "rgba(205, 209, 209, 0.18)",
      "tab_background_text": "rgba(0, 0, 0, 0.54)",
      "bookmark_text": "rgba(0, 0, 0, 0.5)",
      "toolbar_field_text": "rgba(0, 0, 0, 0.48)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{6a8e3026-614e-44c3-bef1-38eecc514005}"
    }
  }
}