Examine source code of Fall Rain

{
  "theme": {
    "images": {
      "theme_frame": "Rain-header_0000_1.png"
    },
    "colors": {
      "frame": "rgba(229,230,232,1)",
      "tab_background_text": "#ffffff"
    }
  },
  "version": "2.0",
  "name": "Fall Rain",
  "manifest_version": 2
}