#DEF0F4

CSS

:root {
  --winter-s-breath: #def0f4;
  --winter-s-breath-rgb: 222 240 244;
  --winter-s-breath-oklch: oklch(0.943 0.02 212.5);
}

.element {
  color: var(--winter-s-breath);
  background-color: hsl(191 50% 91%);
  border-color: oklch(0.943 0.02 212.5);
}

Tailwind CSS v4

@theme {
  --color-winter-s-breath: #def0f4;
  --color-winter-s-breath-50: #eff7f9;
  --color-winter-s-breath-100: #e1eaec;
  --color-winter-s-breath-200: #cbd7d9;
  --color-winter-s-breath-300: #adbabe;
  --color-winter-s-breath-400: #92a2a5;
  --color-winter-s-breath-500: #788a8e;
  --color-winter-s-breath-600: #667578;
  --color-winter-s-breath-700: #515d60;
  --color-winter-s-breath-800: #3b4446;
  --color-winter-s-breath-900: #282f31;
  --color-winter-s-breath-950: #161c1d;
}

SCSS

$winter-s-breath: #def0f4;
$winter-s-breath-rgb: 222, 240, 244;
$winter-s-breath-light: mix(#fff, $winter-s-breath, 20%);
$winter-s-breath-dark: mix(#000, $winter-s-breath, 20%);

.element {
  color: $winter-s-breath;
  box-shadow: 0 0 0 2px rgba($winter-s-breath, 0.35);
}