Examine source code of ClickColor

{
  "manifest_version": 2,
  "name": "ClickColor",
  "version": "1.0.2.0",
  "description": "左クリックで要素に色を付けます",
  "author": "うめほん",
  "icons": {
    "48": "icons/ClickColor-48.png",
    "128": "icons/ClickColor-128.png"
  },
  "permissions": [
    "activeTab"
  ],
  "browser_action": {
    "default_icon": "icons/ClickColor-32.png",
    "default_title": "ClickColor",
    "default_popup": "popup/popup_page.html"
  },
  "web_accessible_resources": [
    "images/ColorBar.png"
  ]
}