Examine source code of Sweet Winter Bird

{
  "name": "Sweet Winter Bird",
  "manifest_version": 2,
  "version": "4.0",
  "theme": {
    "images": {
      "theme_frame": "SweetWinterBirdH.jpg"
    },
    "colors": {
      "frame": "rgba(138, 166, 152, 1)",
      "tab_background_text": "rgba(255, 255, 255, 1)",
      "toolbar": "rgba(138, 166, 152, 0)",
      "bookmark_text": "rgba(255, 255, 255, 1)",
      "toolbar_field": "rgba(138, 166, 152, 0.08)",
      "toolbar_field_text": "rgba(255, 255, 255, 1)",
      "tab_line": "rgba(255, 3, 3, 1)"
    }
  }
}