“There’s a certain Slant of Light, / Winter Afternoons — / That oppresses, like the Heft / Of Cathedral Tunes —,” Emily Dickinson wrote in one of her most famous poems, touching on depression, religion, and humanity’s sense of being overwhelmed by the vastness of the universe. New Haven-born, Brooklyn-based artist Spencer Finch, who uses color in his environmental, site-specific pieces, references Dickinson’s poem in “A Certain Slant of Light: Spencer Finch at the Morgan,” an intoxicating installation that breathes new life into the institution’s Gilbert Court, where visitors can take a break with some food or drink and listen to live music on Friday evenings. Inspired by the Morgan’s renowned collection of medieval, illuminated Books of Hours, Finch has placed colored gels over the windows (including in the elevator) and hung glass panes from the ceiling, which pick up and reflect sunlight to cast rainbow glows across the space. But it’s more than just beautiful reds, blues, greens, yellows, purples, etc., dangling overhead and lighting up the wood-paneled floor; it is also a calendar, like the Book of Hours, referencing the fall harvest, spring planting, religious feasts, and even Isaac Newton’s birthday. Unique use of color with a scientific/technological edge is a key part of Finch’s oeuvre; his “The River That Flows Both Ways” on the High Line consists of colored glass panes based on individual pixels from photographs he took of the Hudson River, and for the recent Creative Time “Drifting in Daylight” group show in Central Park he contributed “Sunset (Central Park),” a truck that served ice cream whose color changed based on the heat of the sun. “A Certain Slant of Light” opened in June 2014, and it has been fascinating watching it morph with the turn of the seasons, but there’s nothing quite like seeing it on a bright and sunny summer day, casting its charming glow for all to see.