#AB631F

CSS

:root {
  --light-brown: #ab631f;
  --light-brown-rgb: 171 99 31;
  --light-brown-oklch: oklch(0.57 0.121 58.8);
}

.element {
  color: var(--light-brown);
  background-color: hsl(29 69% 40%);
  border-color: oklch(0.57 0.121 58.8);
}

Tailwind CSS v4

@theme {
  --color-light-brown: #ab631f;
  --color-light-brown-50: #ffeed3;
  --color-light-brown-100: #ffdfc0;
  --color-light-brown-200: #fbc9a0;
  --color-light-brown-300: #e5a976;
  --color-light-brown-400: #d38c51;
  --color-light-brown-500: #c06f22;
  --color-light-brown-600: #a25e1f;
  --color-light-brown-700: #824b19;
  --color-light-brown-800: #613611;
  --color-light-brown-900: #44250b;
  --color-light-brown-950: #2c1301;
}

SCSS

$light-brown: #ab631f;
$light-brown-rgb: 171, 99, 31;
$light-brown-light: mix(#fff, $light-brown, 20%);
$light-brown-dark: mix(#000, $light-brown, 20%);

.element {
  color: $light-brown;
  box-shadow: 0 0 0 2px rgba($light-brown, 0.35);
}