Gray provides the visual weight against which Barragán’s saturated colors become luminous — lava, stone paving, cement and recinto rather than a neutral default. It is not a clean neutral either: brown, green and blue undertones emerge depending on moisture, weather and reflected light. Dry volcanic stone appears lighter and warmer; wet stone turns darker, cooler and more reflective.
The volcanic ground of El Pedregal offered this palette ready-made: charcoal and mineral gray that ground pink, white and ochre walls in their site. Moss, grass and moisture gradually introduce green into what first reads as a flat neutral, so a “gray” surface outdoors is rarely gray for long.