Examine source code of Test Pilot in Space

{
  "theme": {
    "images": {
      "theme_frame": "header.png"
    },
    "colors": {
      "frame": "#f0f0f0",
      "tab_background_text": "#292929"
    }
  },
  "version": "2.0",
  "name": "Test Pilot in Space",
  "manifest_version": 2,
  "description": "A theme celebrating the <a rel=\"nofollow\" href=\"https://outgoing.prod.mozaws.net/v1/bdf0940efb9a34b22f303f7bf5fe8daed099561138715d909d28321a73989958/https%3A//testpilot.firefox.com\">Firefox Test Pilot program</a>!"
}