Examine source code of ColRand

{
  "manifest_version": 2,
  "name": "ColRand",
  "version": "0.1",
  "description": "Randomizes the colours on all webpages to add some spice to your web experience.",
  "icons": {
    "48": "img.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*/*"
      ],
      "js": [
        "colrand.js"
      ]
    }
  ]
}