The “Legacy Theme” is contained in all GPL Packages.
http://support.wdc.com/product/download.asp?groupid=1010&sid=134&lang=en
Download, Extract, and look for it in …
RV_3.03.13_G\RV_3.03.13_G\src\libs\RES_RV folder.
(if you download other packages, then the RV_ number will be that Firmware)