#C34D53

CSS

:root {
  --autumn-fire: #c34d53;
  --autumn-fire-rgb: 195 77 83;
  --autumn-fire-oklch: oklch(0.578 0.151 20.1);
}

.element {
  color: var(--autumn-fire);
  background-color: hsl(357 50% 53%);
  border-color: oklch(0.578 0.151 20.1);
}

Tailwind CSS v4

@theme {
  --color-autumn-fire: #c34d53;
  --color-autumn-fire-50: #ffe5e2;
  --color-autumn-fire-100: #ffd5d1;
  --color-autumn-fire-200: #ffbbb7;
  --color-autumn-fire-300: #fb9794;
  --color-autumn-fire-400: #ea7678;
  --color-autumn-fire-500: #d8535b;
  --color-autumn-fire-600: #b6484d;
  --color-autumn-fire-700: #93393d;
  --color-autumn-fire-800: #6d282e;
  --color-autumn-fire-900: #4d1b1f;
  --color-autumn-fire-950: #330b0f;
}

SCSS

$autumn-fire: #c34d53;
$autumn-fire-rgb: 195, 77, 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);
}