EliteHW has posted a modding article on changing the led in your floppy drive.

The second in the EliteHW series of case modding articles is aimed at the floppy drive. The floppy drive has become less and less useful since the advent of the zip drive and cdrw's. However, I use my floppy drive frequently enough to merit spending the time to change the led's to a more preferable color. I have been working on an all blue mod for some time so I hope to continue the trend!