Examine source code of jack skellington_

{
  "theme": {
    "images": {
      "theme_frame": ".png"
    },
    "colors": {
      "frame": "#545151",
      "tab_background_text": "#545151"
    }
  },
  "version": "2.0",
  "name": "jack skellington_",
  "manifest_version": 2
}