Red-Letter Day

CSS

:root {
  --red-letter-day: #cc0055;
  --red-letter-day-rgb: 204 0 85;
  --red-letter-day-oklch: oklch(0.541 0.217 8.6);
}

.element {
  color: var(--red-letter-day);
  background-color: hsl(335 100% 40%);
  border-color: oklch(0.541 0.217 8.6);
}

Tailwind CSS v4

@theme {
  --color-red-letter-day: #cc0055;
  --color-red-letter-day-50: #ffdce6;
  --color-red-letter-day-100: #ffcad6;
  --color-red-letter-day-200: #ffacbe;
  --color-red-letter-day-300: #ff839d;
  --color-red-letter-day-400: #ff5984;
  --color-red-letter-day-500: #f11a69;
  --color-red-letter-day-600: #cb1d59;
  --color-red-letter-day-700: #a41847;
  --color-red-letter-day-800: #7a0f36;
  --color-red-letter-day-900: #560a25;
  --color-red-letter-day-950: #3a0013;
}

SCSS

$red-letter-day: #cc0055;
$red-letter-day-rgb: 204, 0, 85;
$red-letter-day-light: mix(#fff, $red-letter-day, 20%);
$red-letter-day-dark: mix(#000, $red-letter-day, 20%);

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