Examine source code of Angel Song

{
  "name": "Angel Song",
  "manifest_version": 2,
  "version": "5.0",
  "theme": {
    "images": {
      "theme_frame": "header.png"
    },
    "colors": {
      "frame": "rgba(132, 140, 134, 1)",
      "tab_background_text": "rgba(255, 255, 255, 1)",
      "toolbar": "rgba(132, 140, 134, 0)",
      "bookmark_text": "rgba(255, 250, 250, 1)",
      "toolbar_field": "rgba(132, 140, 134, 0.04)",
      "toolbar_field_text": "rgba(255, 255, 255, 1)",
      "tab_line": "rgba(255, 255, 255, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{106eee74-6a1b-4a02-bd4f-4ebdba018c0a}"
    }
  }
}