#03060D

CSS

:root {
  --eight-ball: #03060d;
  --eight-ball-rgb: 3 6 13;
  --eight-ball-oklch: oklch(0.121 0.019 259);
}

.element {
  color: var(--eight-ball);
  background-color: hsl(222 63% 3%);
  border-color: oklch(0.121 0.019 259);
}

Tailwind CSS v4

@theme {
  --color-eight-ball: #03060d;
  --color-eight-ball-50: #f2f5fb;
  --color-eight-ball-100: #e4e8ee;
  --color-eight-ball-200: #d0d4dd;
  --color-eight-ball-300: #b2b8c2;
  --color-eight-ball-400: #989faa;
  --color-eight-ball-500: #7f8793;
  --color-eight-ball-600: #6b727d;
  --color-eight-ball-700: #565b64;
  --color-eight-ball-800: #3e4349;
  --color-eight-ball-900: #2b2e33;
  --color-eight-ball-950: #181b1e;
}

SCSS

$eight-ball: #03060d;
$eight-ball-rgb: 3, 6, 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);
}