#D21F41

CSS

:root {
  --sovereign-red: #d21f41;
  --sovereign-red-rgb: 210 31 65;
  --sovereign-red-oklch: oklch(0.558 0.208 18.6);
}

.element {
  color: var(--sovereign-red);
  background-color: hsl(349 74% 47%);
  border-color: oklch(0.558 0.208 18.6);
}

Tailwind CSS v4

@theme {
  --color-sovereign-red: #d21f41;
  --color-sovereign-red-50: #ffdedc;
  --color-sovereign-red-100: #ffccca;
  --color-sovereign-red-200: #ffafae;
  --color-sovereign-red-300: #ff8789;
  --color-sovereign-red-400: #ff5e6d;
  --color-sovereign-red-500: #f1284d;
  --color-sovereign-red-600: #cb2642;
  --color-sovereign-red-700: #a41f34;
  --color-sovereign-red-800: #7a1428;
  --color-sovereign-red-900: #560d1a;
  --color-sovereign-red-950: #3a000b;
}

SCSS

$sovereign-red: #d21f41;
$sovereign-red-rgb: 210, 31, 65;
$sovereign-red-light: mix(#fff, $sovereign-red, 20%);
$sovereign-red-dark: mix(#000, $sovereign-red, 20%);

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