Final answer:
The house in New Castle County, Delaware designed by Robert Venturi and his colleagues in 1980 C.E. exemplifies the Postmodern architectural style, featuring a mix of traditional elements and modern concepts.
Step-by-step explanation:
The architectural style of the house in New Castle County, Delaware, U.S. designed by Robert Venturi, John Rauch, and Denise Scott Brown in 1980 C.E. is Postmodernism. This style is distinguished by its blend of traditional architectural elements with modern concepts, often including an eclectic mix of historical styles and a sense of playfulness and irony. The work of Venturi, Rauch, and Scott Brown is known for embodying the ideals of the Postmodern architectural movement, contrasting the pure forms and simplicity of modernism with more complex and contextual designs.