#E41B32

CSS

:root {
  --transfusion: #e41b32;
  --transfusion-rgb: 228 27 50;
  --transfusion-oklch: oklch(0.587 0.226 23.8);
}

.element {
  color: var(--transfusion);
  background-color: hsl(353 79% 50%);
  border-color: oklch(0.587 0.226 23.8);
}

Tailwind CSS v4

@theme {
  --color-transfusion: #e41b32;
  --color-transfusion-50: #ffddd4;
  --color-transfusion-100: #ffcac1;
  --color-transfusion-200: #ffaca1;
  --color-transfusion-300: #ff8279;
  --color-transfusion-400: #ff5659;
  --color-transfusion-500: #f90632;
  --color-transfusion-600: #d2132c;
  --color-transfusion-700: #a91122;
  --color-transfusion-800: #7f081b;
  --color-transfusion-900: #5a0612;
  --color-transfusion-950: #3c0004;
}

SCSS

$transfusion: #e41b32;
$transfusion-rgb: 228, 27, 50;
$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);
}