Examine source code of City Background

{
  "name": "ac33356c8c9881c60362eb23bd10982f",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "ac98e8cb9f5ed48f2c1216591c8dbfda.jpg"
    },
    "colors": {
      "frame": "rgba(9, 19, 41, 1)",
      "tab_background_text": "rgba(255, 255, 255, 1)",
      "toolbar": "rgba(255, 255, 255, 0.1)",
      "bookmark_text": "rgba(255, 255, 255, 1)",
      "toolbar_field": "rgba(0, 0, 0, 0.35)",
      "toolbar_field_text": "rgba(255, 255, 255, 1)",
      "tab_line": "rgba(255, 255, 255, 0.12)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{77347af7-7d88-46f6-9f33-f1ee9deea22d}"
    }
  }
}