Examine source code of Is That My Shadow

{
  "theme": {
    "images": {
      "theme_frame": "header.png"
    },
    "colors": {
      "frame": "#080808",
      "tab_background_text": "#98fa93"
    }
  },
  "version": "2.0",
  "name": "Is That My Shadow",
  "manifest_version": 2,
  "description": "Is that my brother behind me - or is that my shadow?"
}