#E3EFEF

CSS

:root {
  --winter-s-breath: #e3efef;
  --winter-s-breath-rgb: 227 239 239;
  --winter-s-breath-oklch: oklch(0.943 0.013 196.9);
}

.element {
  color: var(--winter-s-breath);
  background-color: hsl(180 27% 91%);
  border-color: oklch(0.943 0.013 196.9);
}

Tailwind CSS v4

@theme {
  --color-winter-s-breath: #e3efef;
  --color-winter-s-breath-50: #f1f6f6;
  --color-winter-s-breath-100: #e3e9e9;
  --color-winter-s-breath-200: #ced6d6;
  --color-winter-s-breath-300: #b0b9ba;
  --color-winter-s-breath-400: #96a1a1;
  --color-winter-s-breath-500: #7d8989;
  --color-winter-s-breath-600: #6a7474;
  --color-winter-s-breath-700: #555d5d;
  --color-winter-s-breath-800: #3e4444;
  --color-winter-s-breath-900: #2a2f2f;
  --color-winter-s-breath-950: #181b1b;
}

SCSS

$winter-s-breath: #e3efef;
$winter-s-breath-rgb: 227, 239, 239;
$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);
}