[CM] snd gtk background colors

[bil at ccrma.Stanford.EDU]

I think gtk wants to present a "brand" -- the "theme"
writer conjures up a style, including all color choices,
widget geometries, etc, and every program is constrained
to march in step.  snd-gutils.c has a couple attempts
to get around this, but since the gtk developers are
busily subverting it, there's almost no hope it will
work.  The way a theme is defined changes
radically every few months, and it is a large task.
gtk4 will be even worse -- I'll go down fighting...

(Why do they think someone would develop a heavily-graphical
program, and not care what it looks like?)