#DCE6E6

CSS

:root {
  --smoke-and-mirrors: #dce6e6;
  --smoke-and-mirrors-rgb: 220 230 230;
  --smoke-and-mirrors-oklch: oklch(0.917 0.011 197);
}

.element {
  color: var(--smoke-and-mirrors);
  background-color: hsl(180 17% 88%);
  border-color: oklch(0.917 0.011 197);
}

Tailwind CSS v4

@theme {
  --color-smoke-and-mirrors: #dce6e6;
  --color-smoke-and-mirrors-50: #f2f6f6;
  --color-smoke-and-mirrors-100: #e4e9e9;
  --color-smoke-and-mirrors-200: #cfd6d6;
  --color-smoke-and-mirrors-300: #b1b9b9;
  --color-smoke-and-mirrors-400: #98a0a0;
  --color-smoke-and-mirrors-500: #7e8888;
  --color-smoke-and-mirrors-600: #6b7373;
  --color-smoke-and-mirrors-700: #565c5c;
  --color-smoke-and-mirrors-800: #3e4443;
  --color-smoke-and-mirrors-900: #2b2f2f;
  --color-smoke-and-mirrors-950: #181b1b;
}

SCSS

$smoke-and-mirrors: #dce6e6;
$smoke-and-mirrors-rgb: 220, 230, 230;
$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);
}