#E9F4FC

CSS

:root {
  --out-cold: #e9f4fc;
  --out-cold-rgb: 233 244 252;
  --out-cold-oklch: oklch(0.961 0.016 239.1);
}

.element {
  color: var(--out-cold);
  background-color: hsl(205 76% 95%);
  border-color: oklch(0.961 0.016 239.1);
}

Tailwind CSS v4

@theme {
  --color-out-cold: #e9f4fc;
  --color-out-cold-50: #f1f6f9;
  --color-out-cold-100: #e3e9ed;
  --color-out-cold-200: #ced5da;
  --color-out-cold-300: #b1b9bf;
  --color-out-cold-400: #96a0a7;
  --color-out-cold-500: #7d8890;
  --color-out-cold-600: #6a737a;
  --color-out-cold-700: #555c61;
  --color-out-cold-800: #3d4347;
  --color-out-cold-900: #2a2e31;
  --color-out-cold-950: #181b1d;
}

SCSS

$out-cold: #e9f4fc;
$out-cold-rgb: 233, 244, 252;
$out-cold-light: mix(#fff, $out-cold, 20%);
$out-cold-dark: mix(#000, $out-cold, 20%);

.element {
  color: $out-cold;
  box-shadow: 0 0 0 2px rgba($out-cold, 0.35);
}