Useful Cancer Lagoon

Latin ūsus, use — adjectival suffix -ful. As a color modifier, useful implies a clear-and-purpose-serving quality where the hue carries the visual register of helpful-and-supporting design-element. Sits at the crisp-and-functional end of the grid, parallel to practical and serviceable in usage.

Latin cancer, crab-of-the-zodiac. As a color modifier, cancer implies a crab-and-water-sign-and-Moon-ruled-cardinal-water quality, the visual register of Hellenic-Cancer-and-Hercules-Lerna-crab hand-crab-and-water-sign-and-Moon-ruled-cardinal-water Hellenic-Cancer-and-Hercules-Lerna-crab-and-Beehive-Cluster cancer-and-crab-and-water-sign surfaces under Hellenic-Cancer-and-Hercules-Lerna-crab-and-Beehive-Cluster summer-solstice-and-June-and-July cardinal-water-sign-light. Sits at the modifier-and-zodiac end of the grid, parallel to gemini and leo in usage.

A shallow body of saltwater partially or fully enclosed by a barrier — coral atoll lagoons in the Pacific, Venice's Laguna Veneta, the Florida Keys' backcountry. The color refers to the average reflectance of a calm tropical lagoon at midday: a saturated, slightly muted blue-green with the optical clarity of shallow water over white sand. Brighter than reef, cooler than aquamarine, with the postcard weight of a Pacific atoll seen from above.