#EA1536

CSS

:root {
  --transfusion: #ea1536;
  --transfusion-rgb: 234 21 54;
  --transfusion-oklch: oklch(0.597 0.233 22.7);
}

.element {
  color: var(--transfusion);
  background-color: hsl(351 84% 50%);
  border-color: oklch(0.597 0.233 22.7);
}

Tailwind CSS v4

@theme {
  --color-transfusion: #ea1536;
  --color-transfusion-50: #ffdcd4;
  --color-transfusion-100: #ffc9c1;
  --color-transfusion-200: #ffaaa2;
  --color-transfusion-300: #ff8079;
  --color-transfusion-400: #ff525a;
  --color-transfusion-500: #fc0033;
  --color-transfusion-600: #d4002d;
  --color-transfusion-700: #ab0623;
  --color-transfusion-800: #80011c;
  --color-transfusion-900: #5b0312;
  --color-transfusion-950: #3d0005;
}

SCSS

$transfusion: #ea1536;
$transfusion-rgb: 234, 21, 54;
$transfusion-light: mix(#fff, $transfusion, 20%);
$transfusion-dark: mix(#000, $transfusion, 20%);

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