Useful Capricorn 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 capricornus, horned-goat-of-the-zodiac. As a color modifier, capricorn implies a sea-goat-and-earth-sign-and-Saturn-ruled-cardinal-earth quality, the visual register of Hellenic-Capricorn-and-Pan-sea-goat hand-sea-goat-and-earth-sign-and-Saturn-ruled-cardinal-earth Hellenic-Capricorn-and-Pan-sea-goat-and-Babylonian-Suhurmašu capricorn-and-sea-goat-and-earth-sign surfaces under Hellenic-Capricorn-and-Pan-sea-goat-and-Babylonian-Suhurmašu winter-solstice-and-December-and-January cardinal-earth-sign-light. Sits at the modifier-and-zodiac end of the grid, parallel to sagittarius and aquarius 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.