#5165C4

CSS

:root {
  --savoy-blue: #5165c4;
  --savoy-blue-rgb: 81 101 196;
  --savoy-blue-oklch: oklch(0.54 0.149 271.6);
}

.element {
  color: var(--savoy-blue);
  background-color: hsl(230 49% 54%);
  border-color: oklch(0.54 0.149 271.6);
}

Tailwind CSS v4

@theme {
  --color-savoy-blue: #5165c4;
  --color-savoy-blue-50: #e7f3ff;
  --color-savoy-blue-100: #d8e5ff;
  --color-savoy-blue-200: #c0d0ff;
  --color-savoy-blue-300: #9fb2ff;
  --color-savoy-blue-400: #7f97f6;
  --color-savoy-blue-500: #647ce8;
  --color-savoy-blue-600: #5569c3;
  --color-savoy-blue-700: #44549d;
  --color-savoy-blue-800: #2e3e75;
  --color-savoy-blue-900: #1f2b53;
  --color-savoy-blue-950: #0f1838;
}

SCSS

$savoy-blue: #5165c4;
$savoy-blue-rgb: 81, 101, 196;
$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);
}