Yellow

CSS

:root {
  --yellow: #ffff00;
  --yellow-rgb: 255 255 0;
  --yellow-oklch: oklch(0.968 0.211 109.8);
}

.element {
  color: var(--yellow);
  background-color: hsl(60 100% 50%);
  border-color: oklch(0.968 0.211 109.8);
}

Tailwind CSS v4

@theme {
  --color-yellow: #ffff00;
  --color-yellow-50: #f6fcb5;
  --color-yellow-100: #e9ef9c;
  --color-yellow-200: #d7dd6c;
  --color-yellow-300: #bbc114;
  --color-yellow-400: #a9a600;
  --color-yellow-500: #938d00;
  --color-yellow-600: #7c7700;
  --color-yellow-700: #635f00;
  --color-yellow-800: #4b4500;
  --color-yellow-900: #343000;
  --color-yellow-950: #201c00;
}

SCSS

$yellow: #ffff00;
$yellow-rgb: 255, 255, 0;
$yellow-light: mix(#fff, $yellow, 20%);
$yellow-dark: mix(#000, $yellow, 20%);

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