Google Chrome extension for reverting the old-style icons for Twitter Web and Tweetdeck
From here: https://chrome.google.com/webstore/detail/mpiadpcclahclmabiococdaajnicfalj
Install the script below into your Greasemonkey or Tampermonkey. https://raw.githubusercontent.com/foooomio/twitter-icon-come-back/master/userscript.js