#677A76

CSS

:root {
  --underwater-world: #677a76;
  --underwater-world-rgb: 103 122 118;
  --underwater-world-oklch: oklch(0.563 0.023 181.3);
}

.element {
  color: var(--underwater-world);
  background-color: hsl(167 8% 44%);
  border-color: oklch(0.563 0.023 181.3);
}

Tailwind CSS v4

@theme {
  --color-underwater-world: #677a76;
  --color-underwater-world-50: #eef7f6;
  --color-underwater-world-100: #e0eae8;
  --color-underwater-world-200: #cad8d5;
  --color-underwater-world-300: #abbbb8;
  --color-underwater-world-400: #90a39f;
  --color-underwater-world-500: #768b87;
  --color-underwater-world-600: #647672;
  --color-underwater-world-700: #505e5b;
  --color-underwater-world-800: #3a4542;
  --color-underwater-world-900: #28302e;
  --color-underwater-world-950: #161c1b;
}

SCSS

$underwater-world: #677a76;
$underwater-world-rgb: 103, 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);
}