#666900

CSS

:root {
  --serrano-pepper: #666900;
  --serrano-pepper-rgb: 102 105 0;
  --serrano-pepper-oklch: oklch(0.501 0.111 111.7);
}

.element {
  color: var(--serrano-pepper);
  background-color: hsl(62 100% 21%);
  border-color: oklch(0.501 0.111 111.7);
}

Tailwind CSS v4

@theme {
  --color-serrano-pepper: #666900;
  --color-serrano-pepper-50: #f4f9d5;
  --color-serrano-pepper-100: #e7edc3;
  --color-serrano-pepper-200: #d3daa4;
  --color-serrano-pepper-300: #b7be7b;
  --color-serrano-pepper-400: #a0a554;
  --color-serrano-pepper-500: #898d26;
  --color-serrano-pepper-600: #747723;
  --color-serrano-pepper-700: #5c5f1c;
  --color-serrano-pepper-800: #454510;
  --color-serrano-pepper-900: #30300a;
  --color-serrano-pepper-950: #1c1c00;
}

SCSS

$serrano-pepper: #666900;
$serrano-pepper-rgb: 102, 105, 0;
$serrano-pepper-light: mix(#fff, $serrano-pepper, 20%);
$serrano-pepper-dark: mix(#000, $serrano-pepper, 20%);

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