Examine source code of inbetween

{
  "name": "inbetween",
  "manifest_version": 2,
  "version": "5.0",
  "theme": {
    "images": {
      "theme_frame": "5-fertig.png"
    },
    "colors": {
      "frame": "rgba(229, 230, 232, 1)",
      "tab_background_text": "rgba(240, 240, 240, 1)",
      "toolbar": "rgba(0, 0, 0, 0.43)",
      "bookmark_text": "rgba(255, 255, 255, 1)",
      "toolbar_field": "rgba(122, 109, 77, 0.61)",
      "toolbar_field_text": "rgba(255, 255, 255, 1)",
      "tab_line": "rgba(255, 255, 255, 0.65)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{887ba6de-f424-42ef-a15d-9afc5f667765}"
    }
  }
}