Any NetBeans Platform application, not only NetBeans IDE, can benefit from the Darcula LAF for NetBeans IDE.
Here's the standard NetBeans Platform application that you get from the New Project wizard, with the plugin installed:
You'll find that the plugin also installs a tab in the Options window for configuring the LAF:
There are different strategies for installing the plugin into your application. E.g., you can include the plugin source code as a module in your sources or you can let your users install it as a plugin from your Update Center.