Installation of Christo and Jeanne-Claude’s “The Gates” in Central Park has begun. “The $20 million project, a quarter-century in the making and financed by the artists, will go on full view on Feb. 12 and remain until Feb. 27. It is expected to attract thousands of art lovers from around the world. The artists are trying to create “a visual golden river appearing and disappearing through the bare branches of the trees, highlighting the shapes of the footpaths,” according to a brochure explaining the project. The color was chosen to cast a warm glow over the park at a gray time of year.”