Yellow functions in Barragán’s houses as a carrier of light rather than a fixed wall color — most clearly in Casa Gilardi’s long entrance corridor, where a saturated yellow surface washes the passage before it opens onto the cooler blue and red of the pool room. The corridor doesn’t resolve the sequence; it prepares the eye for what follows by changing its state before the room is even seen.
Chucho Reyes is credited with pushing Barragán toward bolder, larger-scale yellow — moving it from small accents onto full architectural planes. The color reads warmest and most saturated under direct sun; in shadow it dulls toward an ochre.