Let me start by saying that if you dont understand what Im about to say, you need more help than a few sentances can give....Im not about to write a photoshop book here
For the RIGHT way (and the way with the most oportunity for ease of use for later changes:
You need to isolate the camoflage variations in thier own layers for each main color.
You should try to isolate the panel lines from each of these layers AFTER the above step, using the best color channel for each individual color scheme that gives the best contrast between the background camoflage, and the lines.
If that doesnt seem to work efficiently, it may be easier (and faster) to just copy the panel lines onto their own layers (reducing the opacity of the layer you copying helps you see what you are doing) by tracing over them.....you do have a graphics pad dont you?
The find edges (and associated filters) probably will help some, but may not work well enough to be any faster in the long run.
Quick and dirty way:
Just isolate the promary camoflage schemes in layers
Pick your new color schemes, and use soft light/color/luminocity options on the brush as shown below....took less than 10 minutes.
