It is afternoon in the summer, and the nave of the Sagrada Família is saturated with warm colors. Shafts of amber and crimson sweep across the stone floor, shift as a cloud passes over Barcelona , then deepen again. Around you, visitors slow without quite realizing it. Some raise their phones — not to capture the architecture, but to step into the light itself, positioning themselves in a pool of orange or gold as if the colours were something you could wear.