#006F96

CSS

:root {
  --chill-of-the-night: #006f96;
  --chill-of-the-night-rgb: 0 111 150;
  --chill-of-the-night-oklch: oklch(0.508 0.103 231.6);
}

.element {
  color: var(--chill-of-the-night);
  background-color: hsl(196 100% 29%);
  border-color: oklch(0.508 0.103 231.6);
}

Tailwind CSS v4

@theme {
  --color-chill-of-the-night: #006f96;
  --color-chill-of-the-night-50: #d9fbff;
  --color-chill-of-the-night-100: #c7efff;
  --color-chill-of-the-night-200: #a9dcfa;
  --color-chill-of-the-night-300: #81c1e4;
  --color-chill-of-the-night-400: #58a9d1;
  --color-chill-of-the-night-500: #2891be;
  --color-chill-of-the-night-600: #257ba1;
  --color-chill-of-the-night-700: #1d6381;
  --color-chill-of-the-night-800: #11495f;
  --color-chill-of-the-night-900: #0b3243;
  --color-chill-of-the-night-950: #001e2b;
}

SCSS

$chill-of-the-night: #006f96;
$chill-of-the-night-rgb: 0, 111, 150;
$chill-of-the-night-light: mix(#fff, $chill-of-the-night, 20%);
$chill-of-the-night-dark: mix(#000, $chill-of-the-night, 20%);

.element {
  color: $chill-of-the-night;
  box-shadow: 0 0 0 2px rgba($chill-of-the-night, 0.35);
}