Examine source code of Winter Bird Song

{
  "name": "Winter Bird Song",
  "manifest_version": 2,
  "version": "3.0",
  "theme": {
    "images": {
      "theme_frame": "WinterBirdSongH2Custom.jpg"
    },
    "colors": {
      "frame": "rgba(178, 202, 240, 1)",
      "tab_background_text": "rgba(255, 255, 255, 1)",
      "toolbar": "rgba(179, 202, 242, 0)",
      "bookmark_text": "rgba(255, 252, 252, 1)",
      "toolbar_field": "rgba(179, 202, 242, 0.08)",
      "toolbar_field_text": "rgba(255, 255, 255, 1)",
      "tab_line": "rgba(255, 255, 255, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{841ff386-e17e-4793-bafc-9aa3a38d3c89}"
    }
  }
}