MILAN – In a world where public art is in danger of deterioration because of maintenance-budget restrictions, forgetfulness, or the sheer complexity of city life, some works are simply too iconic not to refurbish.

Case in point: The 2015 makeover of the “Rainbow Tower” (Torre Arcobaleno) near Milan’s fashionable, design-conscious Garibaldi district.

Built in 1964 as a workaday water tower in the Porta Garibaldi railway yards, the tower was turned into a work of art during the runup to the city’s 1990 hosting of the World Cup, thanks to an initiative of the Sports and Recreation Department of the Milan City Council and the Italian State Railways. The design and architecture firm Original Designers 6R5 Network supervised the project, which gave the tower its rainbow hues by cladding the structure with more than 100,000 ceramic tiles.

In the intervening years, the Torre Arcobaleno became as beloved an icon of Milan as Chicago’s Bean or St. Louis’ Gateway Arch. But life in a major city took its toll and the “rainbow” faded as tiles fell away and concrete crumbled.

Then, as Milan prepared to host another global gathering, the food-and-sustainability-themed Expo Milano 2015, Original Designers 6R5 got together with corporate partners for the comprehensive refurbishment, which involved scrubbing off graffiti, cleaning and replacing tiles, and strengthening the roof.

The makeover was completed in just 71 days at no cost to the city, and the tower was ready to welcome visitors to the Expo, one of whose major exhibitions was a celebration of Italian ceramics.