#006273

CSS

:root {
  --teal-with-it: #006273;
  --teal-with-it-rgb: 0 98 115;
  --teal-with-it-oklch: oklch(0.457 0.081 215);
}

.element {
  color: var(--teal-with-it);
  background-color: hsl(189 100% 23%);
  border-color: oklch(0.457 0.081 215);
}

Tailwind CSS v4

@theme {
  --color-teal-with-it: #006273;
  --color-teal-with-it-50: #ddfbff;
  --color-teal-with-it-100: #cbeffa;
  --color-teal-with-it-200: #aeddeb;
  --color-teal-with-it-300: #88c2d2;
  --color-teal-with-it-400: #63abbc;
  --color-teal-with-it-500: #3a94a7;
  --color-teal-with-it-600: #337d8d;
  --color-teal-with-it-700: #286471;
  --color-teal-with-it-800: #1b4a53;
  --color-teal-with-it-900: #12333a;
  --color-teal-with-it-950: #041f24;
}

SCSS

$teal-with-it: #006273;
$teal-with-it-rgb: 0, 98, 115;
$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);
}