And blue meets green.
The building at the Illinois rail station on DART's Blue Line was once a maintenance shop for the Interurban Railway, which ran between Denison and Waco, along with other routes, until 1948.
Dating to 1914, the shop building has the industrial look of its time and has been on the National Register of Historic Places since 2006.
Inside, however, it has a new role as the headquarters of DART's police department -- the officers who patrol the trains, buses and stations; and their support staff.
The conversion was done with homage to the building's past, seamlessly merging original exposed brick walls and steelwork into the modern workspaces of a police force.
Architects and designers worked with the Texas Historical Commission, the Federal Transit Administration and the city of Dallas to make sure the renovation met preservation standards.
The project has another contemporary touch: It was recently declared among the nation's most environmentally sustainable historical renovations.
And planners were tasked with achieving a LEED silver certification, the third-highest level, from the U.S. Green Building Council. LEED -- Leadership in Energy and Environmental Design -- is a set of international standards for energy-efficient and environmentally friendly methods and materials.
"When the points were added up, the project received not silver, not gold, but platinum," said David Ehrlicher, DART's chief architect. Platinum is the highest level of achievement.
The renovation received credit for its mechanical systems, lighting efficiency, choice of materials and other elements.
Even "Dumpster management," reducing construction waste, counts. The project produced about 95 percent less scrap than a similar renovation might generate.
Other buildings on the national historical register have received LEED platinum certification, but DART believes its police headquarters is the first public-owned example.
With recent rail system expansions, the agency decided its police needed a home on one of the rail lines. The Interurban building, known as the Monroe Shops, was on the Blue Line, and vacant; previous re-use plans hadn't worked out.
Officers and staff moved into the Monroe Shops in March.
The project kept the original building virtually intact by setting the office walls away from the shop walls, essentially putting a smaller new box inside the old structure.
The technique will make future changes easier and helps integrate the past and present.
Conference rooms have floor-to-ceiling windows that show the original brick walls a few feet away. Offices have original green-painted steel girders running overhead and through walls.
Corridors have brick walls that still bear remnants of their old paint.
Natural sunlight from big windows illuminates the officers' two-story-high workout room, which has the post-industrial look of a converted loft apartment. A massive, gray steel beam suspends a heavy bag for boxing workouts.
DART police Lt. Jim Foster, conducting a building tour, said he visited other new police buildings in other states to get tips for DART. Moving into a completely new headquarters is at most a one-time event in an officer's career, he said.
And it's a first for the DART police, which hasn't had a permanent home since the force was founded in 1989. The officers and staff constantly shifted between temporary locations.
Foster joined the force in 1995.
"Since then, I've worked out of seven places," he said. "Having this place is pretty cool."