#C3524F

CSS

:root {
  --autumn-fire: #c3524f;
  --autumn-fire-rgb: 195 82 79;
  --autumn-fire-oklch: oklch(0.584 0.146 24.2);
}

.element {
  color: var(--autumn-fire);
  background-color: hsl(2 49% 54%);
  border-color: oklch(0.584 0.146 24.2);
}

Tailwind CSS v4

@theme {
  --color-autumn-fire: #c3524f;
  --color-autumn-fire-50: #ffe6df;
  --color-autumn-fire-100: #ffd6ce;
  --color-autumn-fire-200: #ffbcb4;
  --color-autumn-fire-300: #f99990;
  --color-autumn-fire-400: #e87973;
  --color-autumn-fire-500: #d65754;
  --color-autumn-fire-600: #b44b48;
  --color-autumn-fire-700: #913b39;
  --color-autumn-fire-800: #6c2a2a;
  --color-autumn-fire-900: #4c1c1c;
  --color-autumn-fire-950: #320c0d;
}

SCSS

$autumn-fire: #c3524f;
$autumn-fire-rgb: 195, 82, 79;
$autumn-fire-light: mix(#fff, $autumn-fire, 20%);
$autumn-fire-dark: mix(#000, $autumn-fire, 20%);

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