Examine source code of this sunset in June

{
  "name": "this sunset in june",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "thissunsetinjune-2.png"
    },
    "colors": {
      "frame": "rgba(112, 64, 4, 1)",
      "tab_background_text": "rgba(255, 255, 255, 1)",
      "toolbar": "rgba(0, 0, 0, 0.52)",
      "bookmark_text": "rgba(255, 255, 255, 1)",
      "toolbar_field": "rgba(255, 140, 0, 0.18)",
      "toolbar_field_text": "rgba(255, 255, 255, 1)",
      "tab_line": "rgba(255, 255, 255, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{b1db6ab0-c2a9-4341-9ade-acfb08ec1d8d}"
    }
  }
}