HARTFORD — A $30 million renovation project is restoring some of the luster to the Travelers tower, a Hartford landmark that once symbolized the city’s reign as America’s insurance capital.The 527-foot-tall tower was New England’s tallest building when it was completed in 1919, but it has been eclipsed several times by modern skyscrapers.“It was looking dirty and kind of worn out,” said Andy Bessette, chief administrative officer of The Travelers Cos.The makeover involves cleaning the granite, replacing 30 miles’ worth of mortar between the stones and restoring decorative moldings. The project began in 2011 after a need for extensive repairs was discovered, and it is expected to take until 2015. The light at the top has also been upgraded, so workers who once climbed up with colored blue panels to celebrate UConn basketball championships can change the color with the push of a button.A century ago, mules, pulleys and ropes were used during construction to raise the pink-hued granite blocks, which came from a quarry in Westerly, R.I. Larger blocks were used at higher levels to give the illusion from the ground that they are the same size. As workers need to repair damage on the facade, they are pulling blocks from other parts of the building where any color difference would not be as noticeable.The 34-story, neoclassical-style building was the seventh-tallest building in the world and a soaring achievement for an insurance industry that has been synonymous with Hartford for centuries.In recent years, the industry has fragmented, with companies selling units and shifting headquarters to other states. But Bessette said the industry is still hugely important to the local economy.“By and large, it’s still a big, big piece of the economy here in Hartford and Connecticut,” he said.Roughly 7 percent of workers — or some 40,000 people — are employed by insurance carriers in greater Hartford, according to state Department of Labor statistics. The figure is 3.6 percent statewide.The tower building hosts about 2,500 of the 7,000 Travelers employees in the Hartford area. Despite its height, Bessette said, the cramped floor plans that were designed to maximize fresh air before the age of air conditioning render it “functionally obsolete.”Project managers say the renovation hasn’t seriously disturbed workers, but it has displaced one resident, a peregrine falcon that nested on the 21st floor of the tower and was filmed by a special Web camera that recorded its activities and chick-rearing. Company officials say they have been assured by state environmental officials that the bird, which was seen flying by the building as recently as two weeks ago, will return once the work is done.