#AC3200

CSS

:root {
  --rust: #ac3200;
  --rust-rgb: 172 50 0;
  --rust-oklch: oklch(0.498 0.166 37.3);
}

.element {
  color: var(--rust);
  background-color: hsl(17 100% 34%);
  border-color: oklch(0.498 0.166 37.3);
}

Tailwind CSS v4

@theme {
  --color-rust: #ac3200;
  --color-rust-50: #ffe6d2;
  --color-rust-100: #ffd6bf;
  --color-rust-200: #ffbc9f;
  --color-rust-300: #ff9876;
  --color-rust-400: #ef7652;
  --color-rust-500: #dd5326;
  --color-rust-600: #bb4723;
  --color-rust-700: #96391b;
  --color-rust-800: #702715;
  --color-rust-900: #4f1b0d;
  --color-rust-950: #340a02;
}

SCSS

$rust: #ac3200;
$rust-rgb: 172, 50, 0;
$rust-light: mix(#fff, $rust, 20%);
$rust-dark: mix(#000, $rust, 20%);

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