Examine source code of greyen

{
  "name": "greyen",
  "manifest_version": 2,
  "version": "3.0",
  "theme": {
    "images": {
      "theme_frame": "gettyimages-713874055-1024x1024.jpg"
    },
    "colors": {
      "frame": "rgba(255, 255, 255, 1)",
      "tab_background_text": "rgba(203, 235, 202, 0.76)",
      "toolbar": "rgba(14, 112, 76, 0.66)",
      "bookmark_text": "rgba(255, 255, 255, 1)",
      "toolbar_field": "rgba(1, 26, 61, 0.49)",
      "toolbar_field_text": "rgba(255, 255, 255, 1)",
      "tab_line": "rgba(1, 24, 61, 0.39)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{c1dfdadf-3fb7-4b06-9c0e-b0a619716128}"
    }
  }
}