Fix readability of chat badge on light screen

README.md

@@ -1,6 +1,6 @@
 [![Version](https://img.shields.io/maven-central/v/org.wildfly.clustering/wildfly-clustering-tomcat?style=for-the-badge&logo=redhat&logoColor=ee0000&label=latest)](https://search.maven.org/artifact/org.wildfly.clustering/wildfly-clustering-tomcat)
 [![License](https://img.shields.io/github/license/wildfly-clustering/wildfly-clustering-tomcat?style=for-the-badge&color=darkgreen&logo=apache&logoColor=d22128)](https://www.apache.org/licenses/LICENSE-2.0)
-[![Project Chat](https://img.shields.io/badge/zulip-chat-white.svg?style=for-the-badge&logo=zulip&logoColor=ffffff)](https://wildfly.zulipchat.com/#narrow/stream/wildfly-clustering)
+[![Project Chat](https://img.shields.io/badge/zulip-chat-lightblue.svg?style=for-the-badge&logo=zulip&logoColor=ffffff)](https://wildfly.zulipchat.com/#narrow/stream/wildfly-clustering)
 
 # wildfly-clustering-tomcat