#BF5153

CSS

:root {
  --autumn-fire: #bf5153;
  --autumn-fire-rgb: 191 81 83;
  --autumn-fire-oklch: oklch(0.577 0.142 21.5);
}

.element {
  color: var(--autumn-fire);
  background-color: hsl(359 46% 53%);
  border-color: oklch(0.577 0.142 21.5);
}

Tailwind CSS v4

@theme {
  --color-autumn-fire: #bf5153;
  --color-autumn-fire-50: #ffe6e2;
  --color-autumn-fire-100: #ffd6d1;
  --color-autumn-fire-200: #ffbdb7;
  --color-autumn-fire-300: #f89a94;
  --color-autumn-fire-400: #e67979;
  --color-autumn-fire-500: #d4585b;
  --color-autumn-fire-600: #b34c4d;
  --color-autumn-fire-700: #903c3e;
  --color-autumn-fire-800: #6b2b2e;
  --color-autumn-fire-900: #4b1d1f;
  --color-autumn-fire-950: #310c0f;
}

SCSS

$autumn-fire: #bf5153;
$autumn-fire-rgb: 191, 81, 83;
$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);
}