[magick-users] selecting all but a color?

[David Vanderson]

Hello,

Does anyone have a suggestion for how to select everything that's not a 
specific color?

For instance, in the following command I'm trying to make everything but 
magenta transparent:
convert -channel "RGBA" -colorspace "rgb" in.png +matte -transparent 
"magenta" -fill "black" -colorize "100%" -background "magenta" -flatten 
-transparent "black" out.png

This does work but seems overly complicated.  I'm hoping there's a more 
straightforward way.

Thanks,
Dave