#01030A

CSS

:root {
  --eight-ball: #01030a;
  --eight-ball-rgb: 1 3 10;
  --eight-ball-oklch: oklch(0.098 0.024 261);
}

.element {
  color: var(--eight-ball);
  background-color: hsl(227 82% 2%);
  border-color: oklch(0.098 0.024 261);
}

Tailwind CSS v4

@theme {
  --color-eight-ball: #01030a;
  --color-eight-ball-50: #f1f5fc;
  --color-eight-ball-100: #e4e8f0;
  --color-eight-ball-200: #cfd4df;
  --color-eight-ball-300: #b1b8c4;
  --color-eight-ball-400: #969fad;
  --color-eight-ball-500: #7d8797;
  --color-eight-ball-600: #6a7280;
  --color-eight-ball-700: #555b66;
  --color-eight-ball-800: #3d434b;
  --color-eight-ball-900: #2a2e34;
  --color-eight-ball-950: #181b20;
}

SCSS

$eight-ball: #01030a;
$eight-ball-rgb: 1, 3, 10;
$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);
}