#AD651A

CSS

:root {
  --light-brown: #ad651a;
  --light-brown-rgb: 173 101 26;
  --light-brown-oklch: oklch(0.576 0.124 60.5);
}

.element {
  color: var(--light-brown);
  background-color: hsl(31 74% 39%);
  border-color: oklch(0.576 0.124 60.5);
}

Tailwind CSS v4

@theme {
  --color-light-brown: #ad651a;
  --color-light-brown-50: #ffeed1;
  --color-light-brown-100: #ffe0be;
  --color-light-brown-200: #fbc99d;
  --color-light-brown-300: #e5a973;
  --color-light-brown-400: #d38c4c;
  --color-light-brown-500: #c06f18;
  --color-light-brown-600: #a25f19;
  --color-light-brown-700: #824c14;
  --color-light-brown-800: #61360e;
  --color-light-brown-900: #442508;
  --color-light-brown-950: #2c1300;
}

SCSS

$light-brown: #ad651a;
$light-brown-rgb: 173, 101, 26;
$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);
}