#EFEFE0

CSS

:root {
  --onion-skin: #efefe0;
  --onion-skin-rgb: 239 239 224;
  --onion-skin-oklch: oklch(0.948 0.02 106.8);
}

.element {
  color: var(--onion-skin);
  background-color: hsl(60 32% 91%);
  border-color: oklch(0.948 0.02 106.8);
}

Tailwind CSS v4

@theme {
  --color-onion-skin: #efefe0;
  --color-onion-skin-50: #f5f6ef;
  --color-onion-skin-100: #e8e8e1;
  --color-onion-skin-200: #d5d5cb;
  --color-onion-skin-300: #b8b8ad;
  --color-onion-skin-400: #9f9f92;
  --color-onion-skin-500: #878778;
  --color-onion-skin-600: #737266;
  --color-onion-skin-700: #5c5c51;
  --color-onion-skin-800: #43433b;
  --color-onion-skin-900: #2e2e28;
  --color-onion-skin-950: #1b1b16;
}

SCSS

$onion-skin: #efefe0;
$onion-skin-rgb: 239, 239, 224;
$onion-skin-light: mix(#fff, $onion-skin, 20%);
$onion-skin-dark: mix(#000, $onion-skin, 20%);

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