#5163CA

CSS

:root {
  --savoy-blue: #5163ca;
  --savoy-blue-rgb: 81 99 202;
  --savoy-blue-oklch: oklch(0.54 0.16 272.5);
}

.element {
  color: var(--savoy-blue);
  background-color: hsl(231 53% 55%);
  border-color: oklch(0.54 0.16 272.5);
}

Tailwind CSS v4

@theme {
  --color-savoy-blue: #5163ca;
  --color-savoy-blue-50: #e7f3ff;
  --color-savoy-blue-100: #d7e5ff;
  --color-savoy-blue-200: #bfcfff;
  --color-savoy-blue-300: #9fb0ff;
  --color-savoy-blue-400: #7f96fc;
  --color-savoy-blue-500: #647aee;
  --color-savoy-blue-600: #5567c9;
  --color-savoy-blue-700: #4453a2;
  --color-savoy-blue-800: #2e3d79;
  --color-savoy-blue-900: #1f2a55;
  --color-savoy-blue-950: #0f173a;
}

SCSS

$savoy-blue: #5163ca;
$savoy-blue-rgb: 81, 99, 202;
$savoy-blue-light: mix(#fff, $savoy-blue, 20%);
$savoy-blue-dark: mix(#000, $savoy-blue, 20%);

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