#607A71

CSS

:root {
  --underwater-world: #607a71;
  --underwater-world-rgb: 96 122 113;
  --underwater-world-oklch: oklch(0.556 0.033 171.9);
}

.element {
  color: var(--underwater-world);
  background-color: hsl(159 12% 43%);
  border-color: oklch(0.556 0.033 171.9);
}

Tailwind CSS v4

@theme {
  --color-underwater-world: #607a71;
  --color-underwater-world-50: #ecf8f4;
  --color-underwater-world-100: #ddece7;
  --color-underwater-world-200: #c7d9d3;
  --color-underwater-world-300: #a7bdb6;
  --color-underwater-world-400: #8ba59c;
  --color-underwater-world-500: #708e84;
  --color-underwater-world-600: #5f786f;
  --color-underwater-world-700: #4c6059;
  --color-underwater-world-800: #374641;
  --color-underwater-world-900: #26312c;
  --color-underwater-world-950: #141d1a;
}

SCSS

$underwater-world: #607a71;
$underwater-world-rgb: 96, 122, 113;
$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);
}