#836653

CSS

:root {
  --pastel-brown: #836653;
  --pastel-brown-rgb: 131 102 83;
  --pastel-brown-oklch: oklch(0.534 0.047 54.7);
}

.element {
  color: var(--pastel-brown);
  background-color: hsl(24 22% 42%);
  border-color: oklch(0.534 0.047 54.7);
}

Tailwind CSS v4

@theme {
  --color-pastel-brown: #836653;
  --color-pastel-brown-50: #fff2e8;
  --color-pastel-brown-100: #f5e4d9;
  --color-pastel-brown-200: #e5d0c1;
  --color-pastel-brown-300: #cbb2a1;
  --color-pastel-brown-400: #b59884;
  --color-pastel-brown-500: #9f7e69;
  --color-pastel-brown-600: #876b59;
  --color-pastel-brown-700: #6c5547;
  --color-pastel-brown-800: #503e33;
  --color-pastel-brown-900: #382b23;
  --color-pastel-brown-950: #221812;
}

SCSS

$pastel-brown: #836653;
$pastel-brown-rgb: 131, 102, 83;
$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);
}