#006B78

CSS

:root {
  --teal-with-it: #006b78;
  --teal-with-it-rgb: 0 107 120;
  --teal-with-it-oklch: oklch(0.483 0.083 209.3);
}

.element {
  color: var(--teal-with-it);
  background-color: hsl(187 100% 24%);
  border-color: oklch(0.483 0.083 209.3);
}

Tailwind CSS v4

@theme {
  --color-teal-with-it: #006b78;
  --color-teal-with-it-50: #dbfcff;
  --color-teal-with-it-100: #c9f0f8;
  --color-teal-with-it-200: #acdee9;
  --color-teal-with-it-300: #84c3d0;
  --color-teal-with-it-400: #5eacb9;
  --color-teal-with-it-500: #3295a4;
  --color-teal-with-it-600: #2d7e8b;
  --color-teal-with-it-700: #24656f;
  --color-teal-with-it-800: #174a51;
  --color-teal-with-it-900: #0f3438;
  --color-teal-with-it-950: #021f23;
}

SCSS

$teal-with-it: #006b78;
$teal-with-it-rgb: 0, 107, 120;
$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);
}