#0A0B0F

CSS

:root {
  --eight-ball: #0a0b0f;
  --eight-ball-rgb: 10 11 15;
  --eight-ball-oklch: oklch(0.15 0.009 274.3);
}

.element {
  color: var(--eight-ball);
  background-color: hsl(228 20% 5%);
  border-color: oklch(0.15 0.009 274.3);
}

Tailwind CSS v4

@theme {
  --color-eight-ball: #0a0b0f;
  --color-eight-ball-50: #f4f5f8;
  --color-eight-ball-100: #e7e8eb;
  --color-eight-ball-200: #d3d4d8;
  --color-eight-ball-300: #b6b7bc;
  --color-eight-ball-400: #9d9ea4;
  --color-eight-ball-500: #84868c;
  --color-eight-ball-600: #707177;
  --color-eight-ball-700: #595b5f;
  --color-eight-ball-800: #414245;
  --color-eight-ball-900: #2d2e30;
  --color-eight-ball-950: #1a1a1c;
}

SCSS

$eight-ball: #0a0b0f;
$eight-ball-rgb: 10, 11, 15;
$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);
}