#E0EEEE

CSS

:root {
  --winter-s-breath: #e0eeee;
  --winter-s-breath-rgb: 224 238 238;
  --winter-s-breath-oklch: oklch(0.939 0.015 196.9);
}

.element {
  color: var(--winter-s-breath);
  background-color: hsl(180 29% 91%);
  border-color: oklch(0.939 0.015 196.9);
}

Tailwind CSS v4

@theme {
  --color-winter-s-breath: #e0eeee;
  --color-winter-s-breath-50: #f0f6f7;
  --color-winter-s-breath-100: #e2e9ea;
  --color-winter-s-breath-200: #cdd6d6;
  --color-winter-s-breath-300: #afbaba;
  --color-winter-s-breath-400: #95a1a1;
  --color-winter-s-breath-500: #7b8989;
  --color-winter-s-breath-600: #687474;
  --color-winter-s-breath-700: #535d5d;
  --color-winter-s-breath-800: #3d4444;
  --color-winter-s-breath-900: #2a2f2f;
  --color-winter-s-breath-950: #171c1b;
}

SCSS

$winter-s-breath: #e0eeee;
$winter-s-breath-rgb: 224, 238, 238;
$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);
}