#D61630

CSS

:root {
  --rare-red: #d61630;
  --rare-red-rgb: 214 22 48;
  --rare-red-oklch: oklch(0.559 0.217 23.1);
}

.element {
  color: var(--rare-red);
  background-color: hsl(352 81% 46%);
  border-color: oklch(0.559 0.217 23.1);
}

Tailwind CSS v4

@theme {
  --color-rare-red: #d61630;
  --color-rare-red-50: #ffded6;
  --color-rare-red-100: #ffccc3;
  --color-rare-red-200: #ffaea5;
  --color-rare-red-300: #ff857d;
  --color-rare-red-400: #ff5b5e;
  --color-rare-red-500: #f51e39;
  --color-rare-red-600: #cf1f32;
  --color-rare-red-700: #a61a27;
  --color-rare-red-800: #7c0f1f;
  --color-rare-red-900: #580a14;
  --color-rare-red-950: #3b0006;
}

SCSS

$rare-red: #d61630;
$rare-red-rgb: 214, 22, 48;
$rare-red-light: mix(#fff, $rare-red, 20%);
$rare-red-dark: mix(#000, $rare-red, 20%);

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