#D83253

CSS

:root {
  --cosmic-red: #d83253;
  --cosmic-red-rgb: 216 50 83;
  --cosmic-red-oklch: oklch(0.585 0.201 15.4);
}

.element {
  color: var(--cosmic-red);
  background-color: hsl(348 68% 52%);
  border-color: oklch(0.585 0.201 15.4);
}

Tailwind CSS v4

@theme {
  --color-cosmic-red: #d83253;
  --color-cosmic-red-50: #ffdfe0;
  --color-cosmic-red-100: #ffcdcf;
  --color-cosmic-red-200: #ffb0b5;
  --color-cosmic-red-300: #ff8891;
  --color-cosmic-red-400: #fe6177;
  --color-cosmic-red-500: #ed3059;
  --color-cosmic-red-600: #c82c4b;
  --color-cosmic-red-700: #a1233c;
  --color-cosmic-red-800: #78172d;
  --color-cosmic-red-900: #550f1f;
  --color-cosmic-red-950: #38010f;
}

SCSS

$cosmic-red: #d83253;
$cosmic-red-rgb: 216, 50, 83;
$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);
}