Certain Via Indigo

Latin certus, fixed / sure — sharing root with English concern and certify. As a color modifier, certain implies a saturated-and-unambiguous quality where the hue declares its character without hesitation. Sits at the bold-and-confident end of the grid, parallel to assured and decisive in usage.

Latin via, road-or-way. As a color modifier, via implies a Latin-road-and-Roman-Via-Appia quality, the visual register of Roman-Via-Appia-and-Via-Aemilia hand-Latin-road-and-Roman-Via-Appia Roman-Via-Appia-and-Via-Aemilia-and-Via-Egnatia via-and-Latin-road surfaces under Roman-Via-Appia-and-Via-Aemilia-and-Via-Egnatia Republican-Rome-and-imperial-road-network basalt-paved-Roman-road-light. Sits at the modifier-and-Latin end of the grid, parallel to arbor and domus in usage.

Indigofera tinctoria, the South Asian legume whose leaves yield the deep blue dye that has clothed humanity for at least four thousand years — Egyptian linen, Mayan textile, the slave-grown plantations of Carolina. The color refers to a freshly indigo-dyed cotton thread: a saturated, slightly violet-shifted deep blue with the slight lustre of a fiber surface oxidized in air. Deeper than cobalt, cooler than royal.