Web extension that adds color to patch files on https://www.drupal.org/
You can download it here: https://chrome.google.com/webstore/detail/drupal-patch-color/acnjdilmnleddbcipfcfbbmhlialepcd https://addons.mozilla.org/fr/firefox/addon/drupal-patch-color/
There is currently no configuration to do, just install the module and go to a patch file on drupal.org