As I understand it earlier in the war Japanese army uniforms were khaki or at least the tunics and trousers were, shirts could vary. The Navy’s SNLF uniforms tended to a more olive colour. As the war progressed the Army also adopted darker, more olive toned uniforms. Naturally enough there would have been transition in the adoption, exhaustion of existing stocks of older kit and the natural vagaries of different manufacturers, dye batches, environmental induced fading etc, etc.
I mix ‘n’ match mine.