Examine source code of Ancient Map from Chrome

{
  "name": "Ancient Map from Chrome",
  "manifest_version": 2,
  "version": "3.0",
  "theme": {
    "images": {
      "theme_frame": "strip1.PNG"
    },
    "colors": {
      "frame": "rgba(0, 0, 0, 1)",
      "tab_background_text": "rgba(0, 0, 0, 1)",
      "toolbar": "rgba(74, 20, 18, 1)",
      "bookmark_text": "rgba(255, 255, 255, 1)",
      "toolbar_field": "rgba(56, 50, 50, 1)",
      "toolbar_field_text": "rgba(255, 255, 255, 1)",
      "tab_line": "rgba(143, 113, 114, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{fc87579d-f8c4-4b4e-84b4-4f1e7f355e09}"
    }
  }
}