#C99026

CSS

:root {
  --end-of-summer: #c99026;
  --end-of-summer-rgb: 201 144 38;
  --end-of-summer-oklch: oklch(0.692 0.133 77.6);
}

.element {
  color: var(--end-of-summer);
  background-color: hsl(39 68% 47%);
  border-color: oklch(0.692 0.133 77.6);
}

Tailwind CSS v4

@theme {
  --color-end-of-summer: #c99026;
  --color-end-of-summer-50: #fff2cb;
  --color-end-of-summer-100: #ffe4b6;
  --color-end-of-summer-200: #f3ce93;
  --color-end-of-summer-300: #dbb065;
  --color-end-of-summer-400: #c99334;
  --color-end-of-summer-500: #b67800;
  --color-end-of-summer-600: #996600;
  --color-end-of-summer-700: #7b5100;
  --color-end-of-summer-800: #5c3a00;
  --color-end-of-summer-900: #412800;
  --color-end-of-summer-950: #291600;
}

SCSS

$end-of-summer: #c99026;
$end-of-summer-rgb: 201, 144, 38;
$end-of-summer-light: mix(#fff, $end-of-summer, 20%);
$end-of-summer-dark: mix(#000, $end-of-summer, 20%);

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