Examine source code of Joker mlem

{
  "name": "Joker mlem",
  "manifest_version": 2,
  "version": "6.0",
  "theme": {
    "images": {
      "theme_frame": "Joker - Copia 2.jpg"
    },
    "colors": {
      "frame": "rgba(3, 3, 3, 1)",
      "tab_background_text": "rgba(255, 255, 255, 1)",
      "toolbar": "rgba(0, 0, 0, 0.28)",
      "bookmark_text": "rgba(72, 122, 62, 1)",
      "toolbar_field": "rgba(0, 0, 0, 0.84)",
      "toolbar_field_text": "rgba(167, 121, 168, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{3ec45e2c-c59e-4aac-8e91-c141bc979c53}"
    }
  }
}