Examine source code of Mountains, Forest, Winter

{
  "name": "Alien Nature Tree",
  "manifest_version": 2,
  "version": "2.0",
  "theme": {
    "images": {
      "theme_frame": "âs.jpg"
    },
    "colors": {
      "frame": "rgba(229, 230, 232, 1)",
      "tab_background_text": "rgba(0, 0, 0, 1)",
      "toolbar": "rgba(41, 255, 237, 1)",
      "toolbar_field": "rgba(31, 255, 218, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{ad719c63-68bf-4ff3-916b-1d5057067a40}"
    }
  }
}