Re: set-background-color

[Richard Stallman]

    In interactive usage, set-background-color provides completion, to ease 
    the burden of typing the long color names.  The fact that you cannot 
    choose hex notation there is a side effect of that completion.  I think 
    completion is more important than the ability to use arbitrary hex values 
    interactively, in this case.

It ought to be possible to support both forms, and provide completion
that works only in the case of the color names and is a no-op for #
colors.  That would be a good thing to do.