At 323 feet (98 m), the towers are the tallest two buildings in Orange County with 400 Spectrum being 3 inches (76 mm) taller than its twin.

The Irvine Company-owned towers were designed by New York-based Pei Cobb Freed & Partners with Michael Bischoff acting as lead architect on the project.

[1] In January 2016, car manufacturer Mazda, who had previously operated its North American headquarters in Irvine since 1987, announced it would move its offices to the new complex.

[4] In September 2017, software firm Cylance was announced as the lead tenant for 400 Spectrum, set to occupy 136,000 square feet (12,600 m2) on floors 6 through 11.

Email company SendGrid was also announced as a major tenant, contracted for 22,000 square feet (2,000 m2) on the fourth floor.

The presence of tech company tenants in the buildings was noted due to the tendency for such businesses to occupy spread-out campuses, such as Infinite Loop and Googleplex.

[5] The two towers were designed by New York-based architectural firm Pei Cobb Freed & Partners with Michael Bischoff serving as the project's lead.

When 200 Spectrum's plans were announced in 2014, a company spokesman said that the point of its height was to maximize office space rather than to compete for the title of the tallest building in a given region, as has been the case with many skyscraper projects around the world.