Undertaker

manifest.json

{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "manifest_version": 2,
  "content_scripts": [
    {
      "css": [
        "undertaker.css"
      ],
      "matches": [
        "http://*/*",
        "https://*/*"
      ]
    }
  ],
  "description": "Underlines every single link; great for color-blind folks who can't stand the 'just change the color' trend.",
  "name": "Undertaker",
  "version": "3.0"
}