You are correct in your assumption. The SE version is silver. There are two differences between the LE and SE. SCSI is optional on the LE but standard on the SE and there are an additional 200 songs included on the hard drive of the LE version for a total of 400 songs.
There is no reason to install the SE operating system into the LE model. There are no differences in the operating system of these two instruments. One small exception probably is that the SE O.S. displays WK-8 SE upon boot-up where the LE displays WK-8 LE (that is a guess since I have not actually seen the SE version myself.
I hope that answers your question. If not, let me know.
[This message has been edited by WDMcM (edited 03-18-2004).]