#00687E

CSS

:root {
  --teal-with-it: #00687e;
  --teal-with-it-rgb: 0 104 126;
  --teal-with-it-oklch: oklch(0.478 0.086 219.1);
}

.element {
  color: var(--teal-with-it);
  background-color: hsl(190 100% 25%);
  border-color: oklch(0.478 0.086 219.1);
}

Tailwind CSS v4

@theme {
  --color-teal-with-it: #00687e;
  --color-teal-with-it-50: #dbfcff;
  --color-teal-with-it-100: #c9effd;
  --color-teal-with-it-200: #acddef;
  --color-teal-with-it-300: #85c2d7;
  --color-teal-with-it-400: #5fabc1;
  --color-teal-with-it-500: #3393ad;
  --color-teal-with-it-600: #2e7d92;
  --color-teal-with-it-700: #246475;
  --color-teal-with-it-800: #174a56;
  --color-teal-with-it-900: #0f333c;
  --color-teal-with-it-950: #021f26;
}

SCSS

$teal-with-it: #00687e;
$teal-with-it-rgb: 0, 104, 126;
$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);
}