Examine source code of Duck Theme

{
  "name": "Duck Theme",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "walking_duck.apng.png"
    },
    "colors": {
      "frame": "rgba(255, 255, 255, 1)",
      "tab_background_text": "rgba(0, 0, 0, 1)",
      "tab_line": "rgba(251, 100, 0, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{143b3836-be5c-4314-ad90-f096dd9733bd}"
    }
  }
}