#607C78

CSS

:root {
  --underwater-world: #607c78;
  --underwater-world-rgb: 96 124 120;
  --underwater-world-oklch: oklch(0.563 0.033 185.6);
}

.element {
  color: var(--underwater-world);
  background-color: hsl(171 13% 43%);
  border-color: oklch(0.563 0.033 185.6);
}

Tailwind CSS v4

@theme {
  --color-underwater-world: #607c78;
  --color-underwater-world-50: #ebf8f7;
  --color-underwater-world-100: #dcecea;
  --color-underwater-world-200: #c5d9d7;
  --color-underwater-world-300: #a5bdba;
  --color-underwater-world-400: #89a5a1;
  --color-underwater-world-500: #6e8e89;
  --color-underwater-world-600: #5d7874;
  --color-underwater-world-700: #4b605d;
  --color-underwater-world-800: #364643;
  --color-underwater-world-900: #25312f;
  --color-underwater-world-950: #131d1b;
}

SCSS

$underwater-world: #607c78;
$underwater-world-rgb: 96, 124, 120;
$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);
}