#C93333

CSS

:root {
  --smouldering-red: #c93333;
  --smouldering-red-rgb: 201 51 51;
  --smouldering-red-oklch: oklch(0.554 0.187 25.8);
}

.element {
  color: var(--smouldering-red);
  background-color: hsl(0 60% 49%);
  border-color: oklch(0.554 0.187 25.8);
}

Tailwind CSS v4

@theme {
  --color-smouldering-red: #c93333;
  --color-smouldering-red-50: #ffe2d8;
  --color-smouldering-red-100: #ffd1c5;
  --color-smouldering-red-200: #ffb5a8;
  --color-smouldering-red-300: #ff8f81;
  --color-smouldering-red-400: #f96a62;
  --color-smouldering-red-500: #e83f3e;
  --color-smouldering-red-600: #c43836;
  --color-smouldering-red-700: #9e2c2b;
  --color-smouldering-red-800: #761e20;
  --color-smouldering-red-900: #531415;
  --color-smouldering-red-950: #370407;
}

SCSS

$smouldering-red: #c93333;
$smouldering-red-rgb: 201, 51, 51;
$smouldering-red-light: mix(#fff, $smouldering-red, 20%);
$smouldering-red-dark: mix(#000, $smouldering-red, 20%);

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