Dave Holland <dave@zenda.demon.co.uk> has this to say about the 16bpp and
32bpp support:

There remains one intermittent bug which can sometimes be demonstrated          
by running floatbg, killing it, and running xcolorsel; the background           
colour doesn't "stick" after floatbg exits. I've an idea how to fix             
that but haven't done it yet. Apart from that I haven't encountered any         
problems with it.
