#B55C1F

CSS

:root {
  --polished-copper: #b55c1f;
  --polished-copper-rgb: 181 92 31;
  --polished-copper-oklch: oklch(0.572 0.135 50.3);
}

.element {
  color: var(--polished-copper);
  background-color: hsl(24 71% 42%);
  border-color: oklch(0.572 0.135 50.3);
}

Tailwind CSS v4

@theme {
  --color-polished-copper: #b55c1f;
  --color-polished-copper-50: #ffebd2;
  --color-polished-copper-100: #ffdcbf;
  --color-polished-copper-200: #ffc59f;
  --color-polished-copper-300: #eea475;
  --color-polished-copper-400: #dd8550;
  --color-polished-copper-500: #ca6721;
  --color-polished-copper-600: #ab571f;
  --color-polished-copper-700: #894618;
  --color-polished-copper-800: #673212;
  --color-polished-copper-900: #48220b;
  --color-polished-copper-950: #2f1001;
}

SCSS

$polished-copper: #b55c1f;
$polished-copper-rgb: 181, 92, 31;
$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);
}