#E81311

CSS

:root {
  --breath-of-fire: #e81311;
  --breath-of-fire-rgb: 232 19 17;
  --breath-of-fire-oklch: oklch(0.589 0.235 28.8);
}

.element {
  color: var(--breath-of-fire);
  background-color: hsl(1 86% 49%);
  border-color: oklch(0.589 0.235 28.8);
}

Tailwind CSS v4

@theme {
  --color-breath-of-fire: #e81311;
  --color-breath-of-fire-50: #ffddcd;
  --color-breath-of-fire-100: #ffcab8;
  --color-breath-of-fire-200: #ffac96;
  --color-breath-of-fire-300: #ff8169;
  --color-breath-of-fire-400: #ff5344;
  --color-breath-of-fire-500: #fc0000;
  --color-breath-of-fire-600: #d50609;
  --color-breath-of-fire-700: #ac0a09;
  --color-breath-of-fire-800: #81030b;
  --color-breath-of-fire-900: #5b0407;
  --color-breath-of-fire-950: #3d0000;
}

SCSS

$breath-of-fire: #e81311;
$breath-of-fire-rgb: 232, 19, 17;
$breath-of-fire-light: mix(#fff, $breath-of-fire, 20%);
$breath-of-fire-dark: mix(#000, $breath-of-fire, 20%);

.element {
  color: $breath-of-fire;
  box-shadow: 0 0 0 2px rgba($breath-of-fire, 0.35);
}