#00020A

CSS

:root {
  --eight-ball: #00020a;
  --eight-ball-rgb: 0 2 10;
  --eight-ball-oklch: oklch(0.088 0.031 257.1);
}

.element {
  color: var(--eight-ball);
  background-color: hsl(228 100% 2%);
  border-color: oklch(0.088 0.031 257.1);
}

Tailwind CSS v4

@theme {
  --color-eight-ball: #00020a;
  --color-eight-ball-50: #f0f6fe;
  --color-eight-ball-100: #e2e8f3;
  --color-eight-ball-200: #ccd5e2;
  --color-eight-ball-300: #aeb8c8;
  --color-eight-ball-400: #939fb1;
  --color-eight-ball-500: #79879b;
  --color-eight-ball-600: #677383;
  --color-eight-ball-700: #525c69;
  --color-eight-ball-800: #3b434d;
  --color-eight-ball-900: #292e36;
  --color-eight-ball-950: #161b21;
}

SCSS

$eight-ball: #00020a;
$eight-ball-rgb: 0, 2, 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);
}