#4D7E81

CSS

:root {
  --submerged: #4d7e81;
  --submerged-rgb: 77 126 129;
  --submerged-oklch: oklch(0.56 0.053 200.7);
}

.element {
  color: var(--submerged);
  background-color: hsl(183 25% 40%);
  border-color: oklch(0.56 0.053 200.7);
}

Tailwind CSS v4

@theme {
  --color-submerged: #4d7e81;
  --color-submerged-50: #e5fafc;
  --color-submerged-100: #d4eef0;
  --color-submerged-200: #bbdbde;
  --color-submerged-300: #98c0c3;
  --color-submerged-400: #79a8ab;
  --color-submerged-500: #5a9194;
  --color-submerged-600: #4d7b7e;
  --color-submerged-700: #3d6265;
  --color-submerged-800: #2b4849;
  --color-submerged-900: #1d3233;
  --color-submerged-950: #0d1e1e;
}

SCSS

$submerged: #4d7e81;
$submerged-rgb: 77, 126, 129;
$submerged-light: mix(#fff, $submerged, 20%);
$submerged-dark: mix(#000, $submerged, 20%);

.element {
  color: $submerged;
  box-shadow: 0 0 0 2px rgba($submerged, 0.35);
}