#B5601F

CSS

:root {
  --polished-copper: #b5601f;
  --polished-copper-rgb: 181 96 31;
  --polished-copper-oklch: oklch(0.579 0.132 52.9);
}

.element {
  color: var(--polished-copper);
  background-color: hsl(26 71% 42%);
  border-color: oklch(0.579 0.132 52.9);
}

Tailwind CSS v4

@theme {
  --color-polished-copper: #b5601f;
  --color-polished-copper-50: #ffecd2;
  --color-polished-copper-100: #ffddbe;
  --color-polished-copper-200: #ffc69e;
  --color-polished-copper-300: #eca574;
  --color-polished-copper-400: #db874e;
  --color-polished-copper-500: #c8691d;
  --color-polished-copper-600: #a9591c;
  --color-polished-copper-700: #884717;
  --color-polished-copper-800: #653310;
  --color-polished-copper-900: #47230a;
  --color-polished-copper-950: #2e1100;
}

SCSS

$polished-copper: #b5601f;
$polished-copper-rgb: 181, 96, 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);
}