Update Readme.md

Author: kamilmysliwiec

Readme.md

@@ -19,7 +19,7 @@
 <a href="https://opencollective.com/nest#backer"><img src="https://opencollective.com/nest/backers/badge.svg" alt="Backers on Open Collective" /></a>
 <a href="https://opencollective.com/nest#sponsor"><img src="https://opencollective.com/nest/sponsors/badge.svg" alt="Sponsors on Open Collective" /></a>
   <a href="https://paypal.me/kamilmysliwiec"><img src="https://img.shields.io/badge/Donate-PayPal-dc3d53.svg"/></a>
-<img src="https://img.shields.io/badge/👌-Production Ready-00ddcc.svg"/>
+<img src="https://img.shields.io/badge/👌-Production Ready-blue.svg"/>
   <a href="https://twitter.com/nestframework"><img src="https://img.shields.io/twitter/follow/nestframework.svg?style=social&label=Follow"></a>
 </p>
   <!--[![Backers on Open Collective](https://opencollective.com/nest/backers/badge.svg)](https://opencollective.com/nest#backer)