#91704F

CSS

:root {
  --decreasing-brown: #91704f;
  --decreasing-brown-rgb: 145 112 79;
  --decreasing-brown-oklch: oklch(0.57 0.063 66);
}

.element {
  color: var(--decreasing-brown);
  background-color: hsl(30 29% 44%);
  border-color: oklch(0.57 0.063 66);
}

Tailwind CSS v4

@theme {
  --color-decreasing-brown: #91704f;
  --color-decreasing-brown-50: #fff2e3;
  --color-decreasing-brown-100: #f7e5d2;
  --color-decreasing-brown-200: #e7d0b8;
  --color-decreasing-brown-300: #cdb295;
  --color-decreasing-brown-400: #b99777;
  --color-decreasing-brown-500: #a37e59;
  --color-decreasing-brown-600: #8a6b4c;
  --color-decreasing-brown-700: #6e553c;
  --color-decreasing-brown-800: #523e2b;
  --color-decreasing-brown-900: #392b1d;
  --color-decreasing-brown-950: #23180d;
}

SCSS

$decreasing-brown: #91704f;
$decreasing-brown-rgb: 145, 112, 79;
$decreasing-brown-light: mix(#fff, $decreasing-brown, 20%);
$decreasing-brown-dark: mix(#000, $decreasing-brown, 20%);

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