Examine source code of Star sparkle

{
  "name": "Barn find",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "old-painting.png"
    },
    "colors": {
      "frame": "rgba(229, 230, 232, 1)",
      "tab_background_text": "rgba(245, 245, 245, 1)",
      "toolbar": "rgba(87, 87, 87, 0)",
      "bookmark_text": "rgba(245, 245, 245, 1)",
      "toolbar_field": "rgba(43, 30, 29, 0.64)",
      "toolbar_field_text": "rgba(245, 245, 245, 1)",
      "tab_line": "rgba(135, 135, 135, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{f8b4b850-4bae-4e26-bb61-7f75512c942d}"
    }
  }
}