#03080F

CSS

:root {
  --eight-ball: #03080f;
  --eight-ball-rgb: 3 8 15;
  --eight-ball-oklch: oklch(0.131 0.02 248.9);
}

.element {
  color: var(--eight-ball);
  background-color: hsl(215 67% 4%);
  border-color: oklch(0.131 0.02 248.9);
}

Tailwind CSS v4

@theme {
  --color-eight-ball: #03080f;
  --color-eight-ball-50: #f1f6fb;
  --color-eight-ball-100: #e3e8ee;
  --color-eight-ball-200: #ced5dd;
  --color-eight-ball-300: #b0b8c1;
  --color-eight-ball-400: #96a0aa;
  --color-eight-ball-500: #7c8893;
  --color-eight-ball-600: #69737c;
  --color-eight-ball-700: #545c64;
  --color-eight-ball-800: #3d4349;
  --color-eight-ball-900: #2a2e33;
  --color-eight-ball-950: #181b1e;
}

SCSS

$eight-ball: #03080f;
$eight-ball-rgb: 3, 8, 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);
}