#04090E

CSS

:root {
  --eight-ball: #04090e;
  --eight-ball-rgb: 4 9 14;
  --eight-ball-oklch: oklch(0.136 0.015 242.1);
}

.element {
  color: var(--eight-ball);
  background-color: hsl(210 56% 4%);
  border-color: oklch(0.136 0.015 242.1);
}

Tailwind CSS v4

@theme {
  --color-eight-ball: #04090e;
  --color-eight-ball-50: #f2f6f9;
  --color-eight-ball-100: #e4e8ed;
  --color-eight-ball-200: #cfd5da;
  --color-eight-ball-300: #b1b8bf;
  --color-eight-ball-400: #97a0a7;
  --color-eight-ball-500: #7e8890;
  --color-eight-ball-600: #6a737a;
  --color-eight-ball-700: #555c61;
  --color-eight-ball-800: #3e4347;
  --color-eight-ball-900: #2a2e31;
  --color-eight-ball-950: #181b1d;
}

SCSS

$eight-ball: #04090e;
$eight-ball-rgb: 4, 9, 14;
$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);
}