Examine source code of Sky Halloween

{
  "theme": {
    "images": {
      "theme_frame": "header.png"
    },
    "colors": {
      "frame": "#343d4a",
      "tab_background_text": "#ffffff"
    }
  },
  "version": "2.0",
  "name": "Sky Halloween",
  "manifest_version": 2,
  "description": "\"sky_halloween\" from Valve's game \"Team Fortress 2\"."
}