#B55C1B

CSS

:root {
  --polished-copper: #b55c1b;
  --polished-copper-rgb: 181 92 27;
  --polished-copper-oklch: oklch(0.572 0.136 51.2);
}

.element {
  color: var(--polished-copper);
  background-color: hsl(25 74% 41%);
  border-color: oklch(0.572 0.136 51.2);
}

Tailwind CSS v4

@theme {
  --color-polished-copper: #b55c1b;
  --color-polished-copper-50: #ffebd1;
  --color-polished-copper-100: #ffdcbe;
  --color-polished-copper-200: #ffc59e;
  --color-polished-copper-300: #eea474;
  --color-polished-copper-400: #dd854e;
  --color-polished-copper-500: #cb671c;
  --color-polished-copper-600: #ab571b;
  --color-polished-copper-700: #894616;
  --color-polished-copper-800: #673210;
  --color-polished-copper-900: #48220a;
  --color-polished-copper-950: #2f1000;
}

SCSS

$polished-copper: #b55c1b;
$polished-copper-rgb: 181, 92, 27;
$polished-copper-light: mix(#fff, $polished-copper, 20%);
$polished-copper-dark: mix(#000, $polished-copper, 20%);

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