#DCEFF3

CSS

:root {
  --winter-s-breath: #dceff3;
  --winter-s-breath-rgb: 220 239 243;
  --winter-s-breath-oklch: oklch(0.939 0.021 211.8);
}

.element {
  color: var(--winter-s-breath);
  background-color: hsl(190 49% 91%);
  border-color: oklch(0.939 0.021 211.8);
}

Tailwind CSS v4

@theme {
  --color-winter-s-breath: #dceff3;
  --color-winter-s-breath-50: #eff7f9;
  --color-winter-s-breath-100: #e0eaec;
  --color-winter-s-breath-200: #cbd7da;
  --color-winter-s-breath-300: #acbabe;
  --color-winter-s-breath-400: #91a2a6;
  --color-winter-s-breath-500: #778a8e;
  --color-winter-s-breath-600: #657578;
  --color-winter-s-breath-700: #515d60;
  --color-winter-s-breath-800: #3a4446;
  --color-winter-s-breath-900: #282f31;
  --color-winter-s-breath-950: #161c1d;
}

SCSS

$winter-s-breath: #dceff3;
$winter-s-breath-rgb: 220, 239, 243;
$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);
}