#DD3155

CSS

:root {
  --cosmic-red: #dd3155;
  --cosmic-red-rgb: 221 49 85;
  --cosmic-red-oklch: oklch(0.593 0.206 15);
}

.element {
  color: var(--cosmic-red);
  background-color: hsl(347 72% 53%);
  border-color: oklch(0.593 0.206 15);
}

Tailwind CSS v4

@theme {
  --color-cosmic-red: #dd3155;
  --color-cosmic-red-50: #ffdee0;
  --color-cosmic-red-100: #ffcccf;
  --color-cosmic-red-200: #ffafb4;
  --color-cosmic-red-300: #ff8791;
  --color-cosmic-red-400: #ff5e76;
  --color-cosmic-red-500: #ef2a58;
  --color-cosmic-red-600: #ca274b;
  --color-cosmic-red-700: #a2203c;
  --color-cosmic-red-800: #79152d;
  --color-cosmic-red-900: #560e1f;
  --color-cosmic-red-950: #39000e;
}

SCSS

$cosmic-red: #dd3155;
$cosmic-red-rgb: 221, 49, 85;
$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);
}