This is a solid coloring, I would actually be 100% on-board if they went this design and making him primarily green would be a cool idea considering red and green are the primary colors of Robin. Dick took blue, illustrating his separation from the identity, Jason took on the red, illustrating his brash nature and his death as robin, so Tim going green could symbolize his positive progression while still staying true to how much of his identity is tied to his time as Robin.