You're probably wondering how I came about this? Do you really want a glimpse into the genius that is my brain? OK you asked for it. Well I was trying out Gimp for the first time (a fantastic and free piece of photo editing software). I was removing the background of my model pictures and replacing it with a nice gradient. I found that the white sheet I used was not perfectly white and the shadows of the model made parts of it grey which made it really hard for Gimp to tell what was the model and what was useless white space. I thought about it for a moment and decided that I should use a background color that wouldn't be confused with the model. Bright green is what I settled on- so smart! I was then really disappointed because I realized that it's what people have been doing for years and I wasn't going to win any awards. I'm not sure I've seen it applied to wargaming photos though. That must be worth fifty points or something.
This is an awesome video that I found that quickly explains how to get started and use Gimp- give it a look!