#050A11

CSS

:root {
  --dark-rift: #050a11;
  --dark-rift-rgb: 5 10 17;
  --dark-rift-oklch: oklch(0.142 0.018 252.7);
}

.element {
  color: var(--dark-rift);
  background-color: hsl(215 55% 4%);
  border-color: oklch(0.142 0.018 252.7);
}

Tailwind CSS v4

@theme {
  --color-dark-rift: #050a11;
  --color-dark-rift-50: #f2f5fa;
  --color-dark-rift-100: #e4e8ee;
  --color-dark-rift-200: #cfd5dc;
  --color-dark-rift-300: #b1b8c1;
  --color-dark-rift-400: #979fa9;
  --color-dark-rift-500: #7e8792;
  --color-dark-rift-600: #6b727c;
  --color-dark-rift-700: #555b63;
  --color-dark-rift-800: #3e4349;
  --color-dark-rift-900: #2a2e32;
  --color-dark-rift-950: #181b1e;
}

SCSS

$dark-rift: #050a11;
$dark-rift-rgb: 5, 10, 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);
}