Anyone who has ever tried to recolour armor other than shoulders or helms (those don't give any problems) probably has come across a hurdle or two. I'm talking about unlocking and saving the textures correctly in Photoshop. If not done correctly, you will get a random texture loaded on your character instead of the edited and desired texture.
(skip to step 3 if you already know how to unlock the layer)
So how do we do it?
Step 1.
Open the texture you want to edit in Photoshop. You will notice that the layer is locked and is labelled "index".
Step 2.
At the top-left toolbar, go to Image->Mode and select RGB color. The layer has now been unlocked and you can manipulate it in any way.
Step 3.
You can't just save the texture yet or it wont load in WoW. To get it functioning yo need to turn it back into an index layer so go to Image->Mode and select Indexed color, click ok without changing anything in the popup menu.
Step 4.
Now simply save the file as a PNG and convert back to BLP.
Example work:
Here's something I cooked up a few days ago. Yes, I like green. Get over it