#02040C

CSS

:root {
  --eight-ball: #02040c;
  --eight-ball-rgb: 2 4 12;
  --eight-ball-oklch: oklch(0.109 0.024 265.2);
}

.element {
  color: var(--eight-ball);
  background-color: hsl(228 71% 3%);
  border-color: oklch(0.109 0.024 265.2);
}

Tailwind CSS v4

@theme {
  --color-eight-ball: #02040c;
  --color-eight-ball-50: #f2f5fc;
  --color-eight-ball-100: #e4e8f0;
  --color-eight-ball-200: #d0d4df;
  --color-eight-ball-300: #b2b7c4;
  --color-eight-ball-400: #989fad;
  --color-eight-ball-500: #7f8696;
  --color-eight-ball-600: #6b727f;
  --color-eight-ball-700: #565b66;
  --color-eight-ball-800: #3e424b;
  --color-eight-ball-900: #2b2e34;
  --color-eight-ball-950: #181b1f;
}

SCSS

$eight-ball: #02040c;
$eight-ball-rgb: 2, 4, 12;
$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);
}