#DAE6E7

CSS

:root {
  --smoke-and-mirrors: #dae6e7;
  --smoke-and-mirrors-rgb: 218 230 231;
  --smoke-and-mirrors-oklch: oklch(0.916 0.013 202.9);
}

.element {
  color: var(--smoke-and-mirrors);
  background-color: hsl(185 21% 88%);
  border-color: oklch(0.916 0.013 202.9);
}

Tailwind CSS v4

@theme {
  --color-smoke-and-mirrors: #dae6e7;
  --color-smoke-and-mirrors-50: #f1f6f7;
  --color-smoke-and-mirrors-100: #e3e9ea;
  --color-smoke-and-mirrors-200: #ced6d7;
  --color-smoke-and-mirrors-300: #b0b9ba;
  --color-smoke-and-mirrors-400: #96a1a2;
  --color-smoke-and-mirrors-500: #7d898a;
  --color-smoke-and-mirrors-600: #6a7475;
  --color-smoke-and-mirrors-700: #545d5d;
  --color-smoke-and-mirrors-800: #3d4444;
  --color-smoke-and-mirrors-900: #2a2f2f;
  --color-smoke-and-mirrors-950: #181b1c;
}

SCSS

$smoke-and-mirrors: #dae6e7;
$smoke-and-mirrors-rgb: 218, 230, 231;
$smoke-and-mirrors-light: mix(#fff, $smoke-and-mirrors, 20%);
$smoke-and-mirrors-dark: mix(#000, $smoke-and-mirrors, 20%);

.element {
  color: $smoke-and-mirrors;
  box-shadow: 0 0 0 2px rgba($smoke-and-mirrors, 0.35);
}