#04050B

CSS

:root {
  --eight-ball: #04050b;
  --eight-ball-rgb: 4 5 11;
  --eight-ball-oklch: oklch(0.117 0.016 273.8);
}

.element {
  color: var(--eight-ball);
  background-color: hsl(231 47% 3%);
  border-color: oklch(0.117 0.016 273.8);
}

Tailwind CSS v4

@theme {
  --color-eight-ball: #04050b;
  --color-eight-ball-50: #f4f5fa;
  --color-eight-ball-100: #e6e7ed;
  --color-eight-ball-200: #d2d4db;
  --color-eight-ball-300: #b5b7c0;
  --color-eight-ball-400: #9b9ea8;
  --color-eight-ball-500: #828691;
  --color-eight-ball-600: #6e717b;
  --color-eight-ball-700: #585a62;
  --color-eight-ball-800: #404248;
  --color-eight-ball-900: #2c2e32;
  --color-eight-ball-950: #191a1e;
}

SCSS

$eight-ball: #04050b;
$eight-ball-rgb: 4, 5, 11;
$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);
}