#C05455

CSS

:root {
  --autumn-fire: #c05455;
  --autumn-fire-rgb: 192 84 85;
  --autumn-fire-oklch: oklch(0.583 0.139 21.8);
}

.element {
  color: var(--autumn-fire);
  background-color: hsl(359 46% 54%);
  border-color: oklch(0.583 0.139 21.8);
}

Tailwind CSS v4

@theme {
  --color-autumn-fire: #c05455;
  --color-autumn-fire-50: #ffe6e2;
  --color-autumn-fire-100: #ffd7d2;
  --color-autumn-fire-200: #ffbdb8;
  --color-autumn-fire-300: #f79a95;
  --color-autumn-fire-400: #e57a79;
  --color-autumn-fire-500: #d25a5b;
  --color-autumn-fire-600: #b24d4e;
  --color-autumn-fire-700: #8f3d3e;
  --color-autumn-fire-800: #6a2b2e;
  --color-autumn-fire-900: #4b1d1f;
  --color-autumn-fire-950: #310d0f;
}

SCSS

$autumn-fire: #c05455;
$autumn-fire-rgb: 192, 84, 85;
$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);
}