Examine source code of rosdel

{
  "name": "rosdel",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "krzyzowka1 (1).png"
    },
    "colors": {
      "frame": "rgba(229, 230, 232, 1)",
      "tab_background_text": "rgba(250, 242, 242, 1)",
      "toolbar": "rgba(245, 240, 240, 1)",
      "bookmark_text": "rgba(255, 255, 255, 1)",
      "toolbar_field": "rgba(255, 255, 255, 1)",
      "toolbar_field_text": "rgba(255, 247, 247, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{d69d6c7c-27cd-452a-a038-bfd33969ee74}"
    }
  }
}