ImgURL-Chrome-Extension/js/background.js

chrome.runtime.onInstalled.addListener(function() {
	chrome.storage.sync.set({color: '#3aa757'}, function() {
	  console.log("The color is green.");
	});
	chrome.declarativeContent.onPageChanged.removeRules(undefined, function() {
      chrome.declarativeContent.onPageChanged.addRules([{
        conditions: [new chrome.declarativeContent.PageStateMatcher({
          pageUrl: {hostEquals: 'developer.chrome.com'},
        })
        ],
            actions: [new chrome.declarativeContent.ShowPageAction()]
      }]);
    });
});