I've tried contrasting the tunic color and pant colors of my WWII Germans in Field Gray but they ended up looking very similar...I tried shading but it didn't work and it made the pants look rather dirty..What can I do not short of using oven cleaner and stripping the paint off the figures?

If the pants look dirty, you might have a real accurate situation. These guys rolled around in mud and grime for months at a time. Trust me after only two or three days in the field you are one filthy beast. So a "parade ground" depiction while looking great isn't exacly very authentic

what I meant was the it was highlighted and shaded wrong..should I repaint or what?