#C64F52

CSS

:root {
  --autumn-fire: #c64f52;
  --autumn-fire-rgb: 198 79 82;
  --autumn-fire-oklch: oklch(0.585 0.152 21.6);
}

.element {
  color: var(--autumn-fire);
  background-color: hsl(358 51% 54%);
  border-color: oklch(0.585 0.152 21.6);
}

Tailwind CSS v4

@theme {
  --color-autumn-fire: #c64f52;
  --color-autumn-fire-50: #ffe5e0;
  --color-autumn-fire-100: #ffd5d0;
  --color-autumn-fire-200: #ffbbb5;
  --color-autumn-fire-300: #fc9792;
  --color-autumn-fire-400: #eb7676;
  --color-autumn-fire-500: #d85357;
  --color-autumn-fire-600: #b7474a;
  --color-autumn-fire-700: #93393b;
  --color-autumn-fire-800: #6e282c;
  --color-autumn-fire-900: #4d1b1e;
  --color-autumn-fire-950: #330a0e;
}

SCSS

$autumn-fire: #c64f52;
$autumn-fire-rgb: 198, 79, 82;
$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);
}