#636E6E

CSS

:root {
  --wrapped-in-twilight: #636e6e;
  --wrapped-in-twilight-rgb: 99 110 110;
  --wrapped-in-twilight-oklch: oklch(0.529 0.013 196.8);
}

.element {
  color: var(--wrapped-in-twilight);
  background-color: hsl(180 5% 41%);
  border-color: oklch(0.529 0.013 196.8);
}

Tailwind CSS v4

@theme {
  --color-wrapped-in-twilight: #636e6e;
  --color-wrapped-in-twilight-50: #f1f6f6;
  --color-wrapped-in-twilight-100: #e3e9e9;
  --color-wrapped-in-twilight-200: #ced6d6;
  --color-wrapped-in-twilight-300: #b0baba;
  --color-wrapped-in-twilight-400: #96a1a1;
  --color-wrapped-in-twilight-500: #7c8989;
  --color-wrapped-in-twilight-600: #697474;
  --color-wrapped-in-twilight-700: #545d5d;
  --color-wrapped-in-twilight-800: #3d4444;
  --color-wrapped-in-twilight-900: #2a2f2f;
  --color-wrapped-in-twilight-950: #181b1b;
}

SCSS

$wrapped-in-twilight: #636e6e;
$wrapped-in-twilight-rgb: 99, 110, 110;
$wrapped-in-twilight-light: mix(#fff, $wrapped-in-twilight, 20%);
$wrapped-in-twilight-dark: mix(#000, $wrapped-in-twilight, 20%);

.element {
  color: $wrapped-in-twilight;
  box-shadow: 0 0 0 2px rgba($wrapped-in-twilight, 0.35);
}