Examine source code of Fireplace

{
  "name": "Fireplace",
  "manifest_version": 2,
  "version": "2.0",
  "theme": {
    "images": {
      "theme_frame": "pexels-pixabay-266604.jpg"
    },
    "colors": {
      "frame": "rgba(84, 66, 78, 1)",
      "tab_background_text": "rgba(150, 114, 78, 1)",
      "toolbar": "rgba(48, 35, 35, 1)",
      "bookmark_text": "rgba(163, 86, 10, 1)",
      "toolbar_field": "rgba(97, 57, 16, 1)",
      "toolbar_field_text": "rgba(26, 23, 23, 1)",
      "tab_line": "rgba(0, 0, 0, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{325a30e9-ccd0-4681-aeae-54c21bf577e0}"
    }
  }
}