military uniforms change every few years when they can benefit from new textile technology or change to adapt to different environments. I was in from 06 - 10 and had three different issued utility uniforms. BDUs, DCUs, and finally ABUs. Whenever a change is proposed it has go through committees and testing and polls and surveys blah blah blah. 20 different people had there hand in the actual design in the end.
There is no particular person who designed this uniform . Though , The design is of French origin, and is a tradition from the pre-Civil War era .
no one in particular.