Well, it's a test for a dynamically colored set of items.
The original icons were taken from here, a great source of black and white game icons. Very useful if you're planning your project and need some stand it art.
The red channel is the grayscale image, the green channel holds a mask for non metallic, non-colored sections, like rope or bare leather. The blue channel holds a mask for dynamic colors.
The masked areas can have their input adjusted by a three channel input (RGB) from a material, to control hue, saturation and value. This gives a wide array of different colors meaning that no two items generated by the item generation script should look identical.
Here's what they look like when passed through the shader:
Ok, still a bit of an ugly mess... I think I need to start with better material than a faked hightmap from a 2 bit image. :)
Honestly, I think 2d art is my worst area. I'm probably just going to move on and come back to this part when the game is nearly done.