Reposeful Blithe Sky

Latin repōnere, to put back — adjectival suffix -ful. As a color modifier, reposeful implies a clear-and-restful-and-still quality, the calm color of pre-modern monastic cloister-and-refectory meditative-and-silent interior architecture. Sits at the crisp-and-calm end of the grid, parallel to peaceful and placid in usage.

Old English blīthe, joyful-and-kind. As a color modifier, blithe implies a carefree-and-light-hearted-and-cheerful quality, the visual register of Shakespearean-pastoral-and-Forest-of-Arden-blithe hand-carefree-and-light-hearted-and-cheerful Shakespearean-pastoral-and-Forest-of-Arden-and-As-You-Like-It blithe-and-carefree-and-light-hearted-and-cheerful surfaces under Shakespearean-pastoral-and-Forest-of-Arden-and-As-You-Like-It English-greenwood-and-shepherd's-meadow Maytime-light. Sits at the modifier-and-mood end of the grid, parallel to merry and jolly in usage.

The blue of a clear sky at noon — produced by Rayleigh scattering, the preferential dispersion of shorter wavelengths through atmospheric molecules. Air itself is colorless; the color we see is sunlight scattered toward our eyes by every cubic kilometer above. The reference shade is mid-latitude noon under a high pressure system: a clean, slightly green-shifted blue with the luminous depth of light scattered across an entire hemisphere of air.