#DE0040

CSS

:root {
  --red-herring: #de0040;
  --red-herring-rgb: 222 0 64;
  --red-herring-oklch: oklch(0.571 0.229 18.2);
}

.element {
  color: var(--red-herring);
  background-color: hsl(343 100% 44%);
  border-color: oklch(0.571 0.229 18.2);
}

Tailwind CSS v4

@theme {
  --color-red-herring: #de0040;
  --color-red-herring-50: #ffdbda;
  --color-red-herring-100: #ffc9c8;
  --color-red-herring-200: #ffaaab;
  --color-red-herring-300: #ff8085;
  --color-red-herring-400: #ff5369;
  --color-red-herring-500: #f90048;
  --color-red-herring-600: #d2093d;
  --color-red-herring-700: #a90b31;
  --color-red-herring-800: #7e0525;
  --color-red-herring-900: #5a0519;
  --color-red-herring-950: #3c000a;
}

SCSS

$red-herring: #de0040;
$red-herring-rgb: 222, 0, 64;
$red-herring-light: mix(#fff, $red-herring, 20%);
$red-herring-dark: mix(#000, $red-herring, 20%);

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