#C44D4E

CSS

:root {
  --autumn-fire: #c44d4e;
  --autumn-fire-rgb: 196 77 78;
  --autumn-fire-oklch: oklch(0.579 0.153 22.7);
}

.element {
  color: var(--autumn-fire);
  background-color: hsl(359 50% 54%);
  border-color: oklch(0.579 0.153 22.7);
}

Tailwind CSS v4

@theme {
  --color-autumn-fire: #c44d4e;
  --color-autumn-fire-50: #ffe5e0;
  --color-autumn-fire-100: #ffd5cf;
  --color-autumn-fire-200: #ffbbb4;
  --color-autumn-fire-300: #fc9790;
  --color-autumn-fire-400: #eb7674;
  --color-autumn-fire-500: #d95355;
  --color-autumn-fire-600: #b74748;
  --color-autumn-fire-700: #933939;
  --color-autumn-fire-800: #6e282b;
  --color-autumn-fire-900: #4d1b1d;
  --color-autumn-fire-950: #330a0d;
}

SCSS

$autumn-fire: #c44d4e;
$autumn-fire-rgb: 196, 77, 78;
$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);
}