Substance is a free (BSD) look and feel and comes with many skins and configuration options.
It is easy to install and configure. I used substance even for NetBeans in the past.
Java EE 7 Workshops: Bootstrap, Effective, Architectures, June, 13th-15th, Munich's Airport
On demand workshops: Java EE 7 Bootstrap, Effective Java EE 7, Java EE 7 Testing and NEW: Java EE 7 Microservices are available for streaming
A book about rethinking Java EE Patterns