#006475

CSS

:root {
  --teal-with-it: #006475;
  --teal-with-it-rgb: 0 100 117;
  --teal-with-it-oklch: oklch(0.463 0.082 214.6);
}

.element {
  color: var(--teal-with-it);
  background-color: hsl(189 100% 23%);
  border-color: oklch(0.463 0.082 214.6);
}

Tailwind CSS v4

@theme {
  --color-teal-with-it: #006475;
  --color-teal-with-it-50: #dcfcff;
  --color-teal-with-it-100: #caeffa;
  --color-teal-with-it-200: #addeeb;
  --color-teal-with-it-300: #87c2d3;
  --color-teal-with-it-400: #61abbc;
  --color-teal-with-it-500: #3894a8;
  --color-teal-with-it-600: #317d8e;
  --color-teal-with-it-700: #276472;
  --color-teal-with-it-800: #1a4a53;
  --color-teal-with-it-900: #11333a;
  --color-teal-with-it-950: #031f24;
}

SCSS

$teal-with-it: #006475;
$teal-with-it-rgb: 0, 100, 117;
$teal-with-it-light: mix(#fff, $teal-with-it, 20%);
$teal-with-it-dark: mix(#000, $teal-with-it, 20%);

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