#5D7A74

CSS

:root {
  --underwater-world: #5d7a74;
  --underwater-world-rgb: 93 122 116;
  --underwater-world-oklch: oklch(0.555 0.035 180.9);
}

.element {
  color: var(--underwater-world);
  background-color: hsl(168 13% 42%);
  border-color: oklch(0.555 0.035 180.9);
}

Tailwind CSS v4

@theme {
  --color-underwater-world: #5d7a74;
  --color-underwater-world-50: #ebf9f6;
  --color-underwater-world-100: #dcece9;
  --color-underwater-world-200: #c5d9d5;
  --color-underwater-world-300: #a5beb9;
  --color-underwater-world-400: #89a69f;
  --color-underwater-world-500: #6d8e87;
  --color-underwater-world-600: #5d7872;
  --color-underwater-world-700: #4a605c;
  --color-underwater-world-800: #364642;
  --color-underwater-world-900: #25312e;
  --color-underwater-world-950: #131d1b;
}

SCSS

$underwater-world: #5d7a74;
$underwater-world-rgb: 93, 122, 116;
$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);
}