Selenium

CSS

:root {
  --selenium: #777e7a;
  --selenium-rgb: 119 126 122;
  --selenium-oklch: oklch(0.586 0.01 161.2);
}

.element {
  color: var(--selenium);
  background-color: hsl(146 3% 48%);
  border-color: oklch(0.586 0.01 161.2);
}

Tailwind CSS v4

@theme {
  --color-selenium: #777e7a;
  --color-selenium-50: #f3f6f4;
  --color-selenium-100: #e5e9e7;
  --color-selenium-200: #d0d6d3;
  --color-selenium-300: #b3b9b6;
  --color-selenium-400: #99a09c;
  --color-selenium-500: #818884;
  --color-selenium-600: #6d7370;
  --color-selenium-700: #575c59;
  --color-selenium-800: #3f4341;
  --color-selenium-900: #2c2f2d;
  --color-selenium-950: #191b1a;
}

SCSS

$selenium: #777e7a;
$selenium-rgb: 119, 126, 122;
$selenium-light: mix(#fff, $selenium, 20%);
$selenium-dark: mix(#000, $selenium, 20%);

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