#D5E3E5

CSS

:root {
  --smoke-and-mirrors: #d5e3e5;
  --smoke-and-mirrors-rgb: 213 227 229;
  --smoke-and-mirrors-oklch: oklch(0.906 0.015 207.1);
}

.element {
  color: var(--smoke-and-mirrors);
  background-color: hsl(188 24% 87%);
  border-color: oklch(0.906 0.015 207.1);
}

Tailwind CSS v4

@theme {
  --color-smoke-and-mirrors: #d5e3e5;
  --color-smoke-and-mirrors-50: #f0f6f7;
  --color-smoke-and-mirrors-100: #e2e9ea;
  --color-smoke-and-mirrors-200: #cdd6d8;
  --color-smoke-and-mirrors-300: #afbabb;
  --color-smoke-and-mirrors-400: #95a1a3;
  --color-smoke-and-mirrors-500: #7b898b;
  --color-smoke-and-mirrors-600: #687476;
  --color-smoke-and-mirrors-700: #535d5e;
  --color-smoke-and-mirrors-800: #3d4445;
  --color-smoke-and-mirrors-900: #2a2f30;
  --color-smoke-and-mirrors-950: #171b1c;
}

SCSS

$smoke-and-mirrors: #d5e3e5;
$smoke-and-mirrors-rgb: 213, 227, 229;
$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);
}