Examine source code of Browser Add-on

{
  "name": "Browser Add-on",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "t5er4t54t.png"
    },
    "colors": {
      "frame": "rgba(32, 18, 58, 1)",
      "tab_background_text": "rgba(255, 106, 60, 1)",
      "toolbar": "rgba(32, 18, 58, 1)",
      "bookmark_text": "rgba(255, 106, 60, 1)",
      "toolbar_field": "rgba(32, 18, 58, 1)",
      "toolbar_field_text": "rgba(255, 106, 60, 1)",
      "tab_line": "rgba(32, 18, 58, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{52fe93d1-e868-45fe-93d6-a63241d60d45}"
    }
  }
}