#E11F4E

CSS

:root {
  --cosmic-red: #e11f4e;
  --cosmic-red-rgb: 225 31 78;
  --cosmic-red-oklch: oklch(0.588 0.221 15.8);
}

.element {
  color: var(--cosmic-red);
  background-color: hsl(345 76% 50%);
  border-color: oklch(0.588 0.221 15.8);
}

Tailwind CSS v4

@theme {
  --color-cosmic-red: #e11f4e;
  --color-cosmic-red-50: #ffdcdd;
  --color-cosmic-red-100: #ffcacc;
  --color-cosmic-red-200: #ffacb1;
  --color-cosmic-red-300: #ff828c;
  --color-cosmic-red-400: #ff5771;
  --color-cosmic-red-500: #f51052;
  --color-cosmic-red-600: #cf1746;
  --color-cosmic-red-700: #a71438;
  --color-cosmic-red-800: #7c0b2a;
  --color-cosmic-red-900: #58081c;
  --color-cosmic-red-950: #3b000d;
}

SCSS

$cosmic-red: #e11f4e;
$cosmic-red-rgb: 225, 31, 78;
$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);
}