Examine source code of Smarkets Colours

{
  "name": "Smarkets Colours",
  "description": "Changes the green & blue colour scheme of Smarkets to the blue & pink colour scheme seen in Betfair and Matchbook",
  "version": "1.0",
  "manifest_version": 2,
  "icons": {
    "48": "icons/48.png",
    "96": "icons/96.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.smarkets.com/*"
      ],
      "js": [
        "smarketscolours.js"
      ]
    }
  ]
}