#136E91

CSS

:root {
  --chill-of-the-night: #136e91;
  --chill-of-the-night-rgb: 19 110 145;
  --chill-of-the-night-oklch: oklch(0.506 0.096 230.5);
}

.element {
  color: var(--chill-of-the-night);
  background-color: hsl(197 77% 32%);
  border-color: oklch(0.506 0.096 230.5);
}

Tailwind CSS v4

@theme {
  --color-chill-of-the-night: #136e91;
  --color-chill-of-the-night-50: #dbfbff;
  --color-chill-of-the-night-100: #c9eeff;
  --color-chill-of-the-night-200: #acdcf7;
  --color-chill-of-the-night-300: #85c0e0;
  --color-chill-of-the-night-400: #5ea9cc;
  --color-chill-of-the-night-500: #3391b9;
  --color-chill-of-the-night-600: #2d7b9d;
  --color-chill-of-the-night-700: #24627e;
  --color-chill-of-the-night-800: #16485c;
  --color-chill-of-the-night-900: #0f3241;
  --color-chill-of-the-night-950: #021e29;
}

SCSS

$chill-of-the-night: #136e91;
$chill-of-the-night-rgb: 19, 110, 145;
$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);
}