#856650

CSS

:root {
  --pastel-brown: #856650;
  --pastel-brown-rgb: 133 102 80;
  --pastel-brown-oklch: oklch(0.536 0.052 56.7);
}

.element {
  color: var(--pastel-brown);
  background-color: hsl(25 25% 42%);
  border-color: oklch(0.536 0.052 56.7);
}

Tailwind CSS v4

@theme {
  --color-pastel-brown: #856650;
  --color-pastel-brown-50: #fff2e7;
  --color-pastel-brown-100: #f6e4d7;
  --color-pastel-brown-200: #e6cfbf;
  --color-pastel-brown-300: #ccb29e;
  --color-pastel-brown-400: #b79781;
  --color-pastel-brown-500: #a17e65;
  --color-pastel-brown-600: #886b56;
  --color-pastel-brown-700: #6d5544;
  --color-pastel-brown-800: #513e31;
  --color-pastel-brown-900: #382a21;
  --color-pastel-brown-950: #231811;
}

SCSS

$pastel-brown: #856650;
$pastel-brown-rgb: 133, 102, 80;
$pastel-brown-light: mix(#fff, $pastel-brown, 20%);
$pastel-brown-dark: mix(#000, $pastel-brown, 20%);

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