In Java, design an ADT for a two-color, double-stack ADT that consists of a red stack and blue stack and has its operations color-coded of the regular stack ADT operations.

For example, this ADT should support a redPush operation and a bluePush operation. Give an efficient implementation of this ADT using a single array whose capacity is set at some value N that is assumed to always be larger than the sizes of the red and blue stacks combined.