I just did this over the weekend. Try looking at www.bootsplash.org,
and also there is a "hint" at www.linuxfromscratch.org.
See if you missed any steps at those two sites. Mine looks good, but I can't do "silent" mode, for some reason, it jumps into verbose mode during the middle of the boot...
Oh well, still looks cool. I even added the background to all six terminals. Rock on.