Examine source code of Drumcode Rot

{
  "name": "Drumcode Rot",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "d.jpg"
    },
    "colors": {
      "frame": "rgba(232, 233, 235, 1)",
      "tab_background_text": "rgba(255, 0, 0, 1)",
      "toolbar": "rgba(3, 3, 3, 0.14)",
      "bookmark_text": "rgba(255, 0, 0, 1)",
      "toolbar_field": "rgba(112, 112, 112, 0.36)",
      "toolbar_field_text": "rgba(255, 0, 0, 1)",
      "tab_line": "rgba(255, 0, 0, 0.44)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{5955daa5-df7f-4574-8071-4d8ffb77dafc}"
    }
  }
}