Removing a single color from an image

[twostars]

Hi,

I'm new to working with images in PHP.

 

Is there an easy way to remove a single color from an image? Or will I have to write a new function. If so, could you please help out (ie: Which image functions I would most likely have to use, or well better still if it doesn't take too much time, write one yourself?.. =D).

 

Thanks. Appreciate it. I've been scouring the GD library's image functions for any clue, but I can't draw any conclusions.