An early concept for an animated TV series proposal titled Theos Ke Polemos. The colors are a little more painted in feel rather than a cell shaded approach due to the intent for the designs to be CG models. More and more I've seen that 3d cell shading can achieve the feel of weathering and cammo patterns I'm after so future designs are going to be cell shaded.
Generally used as air support cover for FOIL (bio-organic combat mecha) based ground campaigns. Sfika, Greek for Wasp is a strange looking machine often sporting the yellow and black stripes, more like bees actually. The D and E variants are much the same as how WWII aircraft would have slight model changes as refinements were made. The E has a slightly sleeker profile. Clearly a WWII influence is apparent and stated here in the description, something not unusual for sci-fi anime concepts. I guess it's the vast amount of odd and aesthetically interesting designs that came out of the war, especially German weapons that leads this fascination in military concepts.