Examine source code of Watermelon

{
  "name": "Watermelon",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "watermelon.png"
    },
    "colors": {
      "frame": "rgba(229, 230, 232, 1)",
      "tab_background_text": "rgba(244, 76, 89, 1)",
      "toolbar": "rgba(255, 255, 255, 0.6)",
      "bookmark_text": "rgba(244, 76, 89, 1)",
      "toolbar_field": "rgba(255, 255, 255, 1)",
      "toolbar_field_text": "rgba(244, 76, 89, 1)",
      "tab_line": "rgba(255, 255, 255, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{d7e0a9a5-95b5-4170-ba09-56bb0b61b70d}"
    }
  }
}