#623B00

CSS

:root {
  --brown: #623b00;
  --brown-rgb: 98 59 0;
  --brown-oklch: oklch(0.39 0.085 68.8);
}

.element {
  color: var(--brown);
  background-color: hsl(36 100% 19%);
  border-color: oklch(0.39 0.085 68.8);
}

Tailwind CSS v4

@theme {
  --color-brown: #623b00;
  --color-brown-50: #fff2db;
  --color-brown-100: #fbe4ca;
  --color-brown-200: #eccfad;
  --color-brown-300: #d4b188;
  --color-brown-400: #c09566;
  --color-brown-500: #ab7b44;
  --color-brown-600: #90693a;
  --color-brown-700: #74532e;
  --color-brown-800: #563c21;
  --color-brown-900: #3c2915;
  --color-brown-950: #261707;
}

SCSS

$brown: #623b00;
$brown-rgb: 98, 59, 0;
$brown-light: mix(#fff, $brown, 20%);
$brown-dark: mix(#000, $brown, 20%);

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