To do that, you need to decompile both .apk files (from your ROM and from the Galaxy ROM) (I use apk manager to do that) Then compare
"styles.xml" in /res/values folder and transfer the data from the galaxy one to yours...(this xml might be different in Galaxy ROM) And then you only need to re-compile and optimize it...
(As settings.apk is a proprietary ROM apk, you need to decompile/recompile it using HTC/Galaxy framework...)
Good luck with that
EDIT: In the link provided, there is how he did it....
EDIT: He didn't actually make it transparent, he just placed a theme wallpaper in the background instead of White one...