#B35D1F

CSS

:root {
  --polished-copper: #b35d1f;
  --polished-copper-rgb: 179 93 31;
  --polished-copper-oklch: oklch(0.571 0.132 51.6);
}

.element {
  color: var(--polished-copper);
  background-color: hsl(25 70% 41%);
  border-color: oklch(0.571 0.132 51.6);
}

Tailwind CSS v4

@theme {
  --color-polished-copper: #b35d1f;
  --color-polished-copper-50: #ffecd2;
  --color-polished-copper-100: #ffddbf;
  --color-polished-copper-200: #ffc59f;
  --color-polished-copper-300: #eda576;
  --color-polished-copper-400: #dc8650;
  --color-polished-copper-500: #c96821;
  --color-polished-copper-600: #aa591f;
  --color-polished-copper-700: #884719;
  --color-polished-copper-800: #663212;
  --color-polished-copper-900: #48220b;
  --color-polished-copper-950: #2e1101;
}

SCSS

$polished-copper: #b35d1f;
$polished-copper-rgb: 179, 93, 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);
}