Night Flight

CSS

:root {
  --night-flight: #434d5c;
  --night-flight-rgb: 67 77 92;
  --night-flight-oklch: oklch(0.417 0.028 258.4);
}

.element {
  color: var(--night-flight);
  background-color: hsl(216 16% 31%);
  border-color: oklch(0.417 0.028 258.4);
}

Tailwind CSS v4

@theme {
  --color-night-flight: #434d5c;
  --color-night-flight-50: #f0f5fd;
  --color-night-flight-100: #e2e8f2;
  --color-night-flight-200: #cdd5e1;
  --color-night-flight-300: #afb8c6;
  --color-night-flight-400: #949fb0;
  --color-night-flight-500: #7b8799;
  --color-night-flight-600: #687282;
  --color-night-flight-700: #535b68;
  --color-night-flight-800: #3c434c;
  --color-night-flight-900: #292e35;
  --color-night-flight-950: #171b20;
}

SCSS

$night-flight: #434d5c;
$night-flight-rgb: 67, 77, 92;
$night-flight-light: mix(#fff, $night-flight, 20%);
$night-flight-dark: mix(#000, $night-flight, 20%);

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