Examine source code of NIght Sky BG

{
  "name": "NIght",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "3442871.jpg"
    },
    "colors": {
      "frame": "rgba(39, 11, 161, 1)",
      "tab_background_text": "rgba(56, 46, 71, 1)",
      "toolbar": "rgba(29, 0, 84, 1)",
      "bookmark_text": "rgba(122, 129, 199, 1)",
      "toolbar_field": "rgba(122, 129, 199, 1)",
      "toolbar_field_text": "rgba(29, 0, 84, 1)",
      "tab_line": "rgba(56, 46, 71, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{f7f99d1f-ff30-427a-bdf6-9f63b137f450}"
    }
  }
}