#020611

CSS

:root {
  --dark-rift: #020611;
  --dark-rift-rgb: 2 6 17;
  --dark-rift-oklch: oklch(0.123 0.029 259.7);
}

.element {
  color: var(--dark-rift);
  background-color: hsl(224 79% 4%);
  border-color: oklch(0.123 0.029 259.7);
}

Tailwind CSS v4

@theme {
  --color-dark-rift: #020611;
  --color-dark-rift-50: #f1f5fe;
  --color-dark-rift-100: #e3e8f2;
  --color-dark-rift-200: #cdd5e1;
  --color-dark-rift-300: #afb8c7;
  --color-dark-rift-400: #959fb0;
  --color-dark-rift-500: #7b879a;
  --color-dark-rift-600: #687282;
  --color-dark-rift-700: #535b68;
  --color-dark-rift-800: #3c434d;
  --color-dark-rift-900: #292e35;
  --color-dark-rift-950: #171b20;
}

SCSS

$dark-rift: #020611;
$dark-rift-rgb: 2, 6, 17;
$dark-rift-light: mix(#fff, $dark-rift, 20%);
$dark-rift-dark: mix(#000, $dark-rift, 20%);

.element {
  color: $dark-rift;
  box-shadow: 0 0 0 2px rgba($dark-rift, 0.35);
}