Starting with version 0.47, DockBarX supports separate themes for DockBarX, DockX and window list and some cool new themes have already started to show up on websites like DeviantArt.
One theme I really like is called "Brit" (inspired by "Elegant Brit" GTK theme) and comes with everything you need: DockBarX and window list themes as well as two dock (for DockX) themes.
The theme has been created by BigRZA, who has previously created some beautiful DockBarX themes like TonkyBar or the DBX big dock pack.
Brit for DockBarX screenshots:
To install Brit for DockBarX, extract the downloaded archive to your home folder. If this is the first time you're installing a new DockBarX theme manually, there's nothing else you need to do because extracting the archive automatically creates the folder structure (~/.dockbarx/themes).
If not, press CTRL + H to be able to see hidden folders and copy the contents of the themes folder inside .dockbarx to ~/.dockbarx/theme .
Then, launch the DockBarX Preferences window and apply the new theme on both the Appearence tab (for "Theme" and "Window list style") and Dock tab if you use DockX.
Download Brit for DockBarX 0.47+