#DE2651

CSS

:root {
  --cosmic-red: #de2651;
  --cosmic-red-rgb: 222 38 81;
  --cosmic-red-oklch: oklch(0.587 0.215 15.2);
}

.element {
  color: var(--cosmic-red);
  background-color: hsl(346 74% 51%);
  border-color: oklch(0.587 0.215 15.2);
}

Tailwind CSS v4

@theme {
  --color-cosmic-red: #de2651;
  --color-cosmic-red-50: #ffdddf;
  --color-cosmic-red-100: #ffcbce;
  --color-cosmic-red-200: #ffadb3;
  --color-cosmic-red-300: #ff848f;
  --color-cosmic-red-400: #ff5a74;
  --color-cosmic-red-500: #f21e56;
  --color-cosmic-red-600: #cd1f49;
  --color-cosmic-red-700: #a51a3a;
  --color-cosmic-red-800: #7b102c;
  --color-cosmic-red-900: #570a1e;
  --color-cosmic-red-950: #3a000e;
}

SCSS

$cosmic-red: #de2651;
$cosmic-red-rgb: 222, 38, 81;
$cosmic-red-light: mix(#fff, $cosmic-red, 20%);
$cosmic-red-dark: mix(#000, $cosmic-red, 20%);

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