#37225A

CSS

:root {
  --stormy-night: #37225a;
  --stormy-night-rgb: 55 34 90;
  --stormy-night-oklch: oklch(0.31 0.097 297.8);
}

.element {
  color: var(--stormy-night);
  background-color: hsl(263 45% 24%);
  border-color: oklch(0.31 0.097 297.8);
}

Tailwind CSS v4

@theme {
  --color-stormy-night: #37225a;
  --color-stormy-night-50: #f9f0ff;
  --color-stormy-night-100: #ece1ff;
  --color-stormy-night-200: #daccf8;
  --color-stormy-night-300: #beade2;
  --color-stormy-night-400: #a592d1;
  --color-stormy-night-500: #8e78be;
  --color-stormy-night-600: #7865a0;
  --color-stormy-night-700: #605181;
  --color-stormy-night-800: #453b60;
  --color-stormy-night-900: #302943;
  --color-stormy-night-950: #1c162b;
}

SCSS

$stormy-night: #37225a;
$stormy-night-rgb: 55, 34, 90;
$stormy-night-light: mix(#fff, $stormy-night, 20%);
$stormy-night-dark: mix(#000, $stormy-night, 20%);

.element {
  color: $stormy-night;
  box-shadow: 0 0 0 2px rgba($stormy-night, 0.35);
}