#CA3132

CSS

:root {
  --smouldering-red: #ca3132;
  --smouldering-red-rgb: 202 49 50;
  --smouldering-red-oklch: oklch(0.554 0.19 25.7);
}

.element {
  color: var(--smouldering-red);
  background-color: hsl(360 61% 49%);
  border-color: oklch(0.554 0.19 25.7);
}

Tailwind CSS v4

@theme {
  --color-smouldering-red: #ca3132;
  --color-smouldering-red-50: #ffe1d7;
  --color-smouldering-red-100: #ffd0c5;
  --color-smouldering-red-200: #ffb4a7;
  --color-smouldering-red-300: #ff8e80;
  --color-smouldering-red-400: #fa6961;
  --color-smouldering-red-500: #e93d3d;
  --color-smouldering-red-600: #c53635;
  --color-smouldering-red-700: #9e2b2a;
  --color-smouldering-red-800: #761d20;
  --color-smouldering-red-900: #541315;
  --color-smouldering-red-950: #380407;
}

SCSS

$smouldering-red: #ca3132;
$smouldering-red-rgb: 202, 49, 50;
$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);
}