[magick-users] Replace color with a pattern

[Bill Ten Broeck]

Hello.

I'm trying to take an image that has two colors; white and another 
color, and place a background image behind everywhere the non-white 
color exists. Is this doable at this point? Looking through the 
documentation, it *appears* this might be future functionality, however 
I am so new to Image Magick, I may not understand what I'm looking at.

Thanks in advance.