Nimbus Look-and-Feel (click image to enlarge)
This modern cross platform look-and-feel has a very appealing look and integrates well on the different platforms (Windows, Linux and Mac).
Nimbus uses Java 2D vector graphics to draw the user interface (UI), rather than static bitmaps, so the UI can be crisply rendered at any resolution. It has a set of default colors, but you are not required to use them. You can change the colors to match your corporate brand or other color scheme.
It is supported in NetPhantom when running the Client with Java 7 or Java 6 update 23 or better.
There are many websites where you can obtain more information about Nimbus. Here are a few websites: