Examine source code of Grassland Sunset

{
  "name": "Grassland Sunset",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "Grassland-Sunset.png"
    },
    "colors": {
      "frame": "rgba(179, 204, 37, 1)",
      "tab_background_text": "rgba(217, 135, 35, 1)",
      "toolbar": "rgba(219, 123, 40, 1)",
      "bookmark_text": "rgba(128, 117, 64, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{36d487a5-d710-40db-8538-9627bc00cf48}"
    }
  }
}