#05090D

CSS

:root {
  --eight-ball: #05090d;
  --eight-ball-rgb: 5 9 13;
  --eight-ball-oklch: oklch(0.136 0.012 243.1);
}

.element {
  color: var(--eight-ball);
  background-color: hsl(210 44% 4%);
  border-color: oklch(0.136 0.012 243.1);
}

Tailwind CSS v4

@theme {
  --color-eight-ball: #05090d;
  --color-eight-ball-50: #f2f5f8;
  --color-eight-ball-100: #e5e8ec;
  --color-eight-ball-200: #d0d5d9;
  --color-eight-ball-300: #b2b8bd;
  --color-eight-ball-400: #999fa5;
  --color-eight-ball-500: #80878e;
  --color-eight-ball-600: #6c7278;
  --color-eight-ball-700: #565c60;
  --color-eight-ball-800: #3f4346;
  --color-eight-ball-900: #2b2e31;
  --color-eight-ball-950: #191b1d;
}

SCSS

$eight-ball: #05090d;
$eight-ball-rgb: 5, 9, 13;
$eight-ball-light: mix(#fff, $eight-ball, 20%);
$eight-ball-dark: mix(#000, $eight-ball, 20%);

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