Examine source code of Julia Swirl

{
  "theme": {
    "images": {
      "theme_frame": "sea_shell_a_header.jpg"
    },
    "colors": {
      "frame": "#000000",
      "tab_background_text": "#fcfcfc"
    }
  },
  "version": "2.0",
  "name": "Julia Swirl",
  "manifest_version": 2,
  "description": "This is a Julia Fractal layered image."
}