#607A76

CSS

:root {
  --underwater-world: #607a76;
  --underwater-world-rgb: 96 122 118;
  --underwater-world-oklch: oklch(0.558 0.031 184.9);
}

.element {
  color: var(--underwater-world);
  background-color: hsl(171 12% 43%);
  border-color: oklch(0.558 0.031 184.9);
}

Tailwind CSS v4

@theme {
  --color-underwater-world: #607a76;
  --color-underwater-world-50: #ecf8f6;
  --color-underwater-world-100: #ddebe9;
  --color-underwater-world-200: #c6d9d6;
  --color-underwater-world-300: #a7bdba;
  --color-underwater-world-400: #8ba5a1;
  --color-underwater-world-500: #708d89;
  --color-underwater-world-600: #5f7774;
  --color-underwater-world-700: #4c605c;
  --color-underwater-world-800: #374643;
  --color-underwater-world-900: #25302e;
  --color-underwater-world-950: #141d1b;
}

SCSS

$underwater-world: #607a76;
$underwater-world-rgb: 96, 122, 118;
$underwater-world-light: mix(#fff, $underwater-world, 20%);
$underwater-world-dark: mix(#000, $underwater-world, 20%);

.element {
  color: $underwater-world;
  box-shadow: 0 0 0 2px rgba($underwater-world, 0.35);
}