#5F7C77

CSS

:root {
  --underwater-world: #5f7c77;
  --underwater-world-rgb: 95 124 119;
  --underwater-world-oklch: oklch(0.562 0.034 183.4);
}

.element {
  color: var(--underwater-world);
  background-color: hsl(170 13% 43%);
  border-color: oklch(0.562 0.034 183.4);
}

Tailwind CSS v4

@theme {
  --color-underwater-world: #5f7c77;
  --color-underwater-world-50: #ebf9f6;
  --color-underwater-world-100: #dcece9;
  --color-underwater-world-200: #c5d9d6;
  --color-underwater-world-300: #a5bdba;
  --color-underwater-world-400: #89a5a0;
  --color-underwater-world-500: #6d8e88;
  --color-underwater-world-600: #5d7873;
  --color-underwater-world-700: #4a605c;
  --color-underwater-world-800: #364643;
  --color-underwater-world-900: #25312e;
  --color-underwater-world-950: #131d1b;
}

SCSS

$underwater-world: #5f7c77;
$underwater-world-rgb: 95, 124, 119;
$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);
}