Examine source code of starry blue sky

{
  "name": "blue-starry-night",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "blue-starry-night.png"
    },
    "colors": {
      "frame": "rgba(229, 230, 232, 1)",
      "tab_background_text": "rgba(31, 92, 33, 1)",
      "toolbar": "rgba(179, 147, 147, 1)",
      "bookmark_text": "rgba(50, 102, 24, 1)",
      "toolbar_field": "rgba(186, 190, 207, 1)",
      "toolbar_field_text": "rgba(39, 122, 45, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{b2c4bf6c-b120-4ae9-887e-48a307afe2cd}"
    }
  }
}