Plain Quad Robin

Latin planus, flat, level — used as a color modifier since the medieval period for hues that read as undecorated and direct. Plain white, plain blue: moderate saturation, no shift, no surface effect. Sits in the crisp-bucket center, with the implication of restraint rather than absence.

Latin quadrum, square. As a color modifier, quad implies an Oxford-and-Cambridge-college-quadrangle quality, the visual register of Oxford-and-Cambridge-college-quad hand-built four-sided-college-courtyard quad-and-cloister-and-lawn architectural surfaces under Oxford-and-Cambridge college-quadrangle academic light. Sits at the modifier-and-architecture end of the grid, parallel to court and atrium in usage.

The American robin (Turdus migratorius) — though the color refers not to the bird's red breast but to the egg, robin's-egg blue, a pale slightly green-shifted blue produced by biliverdin pigment in the eggshell. The color is the inside surface of a fresh robin's nest at peak laying: a soft, slightly green-shifted pale blue with the matte finish of avian eggshell. Lighter than aqua, cooler than turquoise.