#C83534

CSS

:root {
  --smouldering-red: #c83534;
  --smouldering-red-rgb: 200 53 52;
  --smouldering-red-oklch: oklch(0.554 0.184 25.9);
}

.element {
  color: var(--smouldering-red);
  background-color: hsl(0 59% 49%);
  border-color: oklch(0.554 0.184 25.9);
}

Tailwind CSS v4

@theme {
  --color-smouldering-red: #c83534;
  --color-smouldering-red-50: #ffe2d8;
  --color-smouldering-red-100: #ffd1c6;
  --color-smouldering-red-200: #ffb5a8;
  --color-smouldering-red-300: #ff9082;
  --color-smouldering-red-400: #f86b63;
  --color-smouldering-red-500: #e7413f;
  --color-smouldering-red-600: #c33937;
  --color-smouldering-red-700: #9d2e2b;
  --color-smouldering-red-800: #751f21;
  --color-smouldering-red-900: #531516;
  --color-smouldering-red-950: #370507;
}

SCSS

$smouldering-red: #c83534;
$smouldering-red-rgb: 200, 53, 52;
$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);
}