#E43709

CSS

:root {
  --vulcan-fire: #e43709;
  --vulcan-fire-rgb: 228 55 9;
  --vulcan-fire-oklch: oklch(0.602 0.214 33.7);
}

.element {
  color: var(--vulcan-fire);
  background-color: hsl(13 92% 46%);
  border-color: oklch(0.602 0.214 33.7);
}

Tailwind CSS v4

@theme {
  --color-vulcan-fire: #e43709;
  --color-vulcan-fire-50: #ffe0cb;
  --color-vulcan-fire-100: #ffcfb7;
  --color-vulcan-fire-200: #ffb294;
  --color-vulcan-fire-300: #ff8a67;
  --color-vulcan-fire-400: #ff613f;
  --color-vulcan-fire-500: #f32c00;
  --color-vulcan-fire-600: #cd2900;
  --color-vulcan-fire-700: #a52200;
  --color-vulcan-fire-800: #7c1505;
  --color-vulcan-fire-900: #580e04;
  --color-vulcan-fire-950: #3b0000;
}

SCSS

$vulcan-fire: #e43709;
$vulcan-fire-rgb: 228, 55, 9;
$vulcan-fire-light: mix(#fff, $vulcan-fire, 20%);
$vulcan-fire-dark: mix(#000, $vulcan-fire, 20%);

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