Dark as Night

CSS

:root {
  --dark-as-night: #495252;
  --dark-as-night-rgb: 73 82 82;
  --dark-as-night-oklch: oklch(0.431 0.011 196.7);
}

.element {
  color: var(--dark-as-night);
  background-color: hsl(180 6% 30%);
  border-color: oklch(0.431 0.011 196.7);
}

Tailwind CSS v4

@theme {
  --color-dark-as-night: #495252;
  --color-dark-as-night-50: #f2f6f6;
  --color-dark-as-night-100: #e4e9e9;
  --color-dark-as-night-200: #cfd6d6;
  --color-dark-as-night-300: #b1b9b9;
  --color-dark-as-night-400: #97a1a1;
  --color-dark-as-night-500: #7e8989;
  --color-dark-as-night-600: #6b7474;
  --color-dark-as-night-700: #555c5c;
  --color-dark-as-night-800: #3e4443;
  --color-dark-as-night-900: #2b2f2f;
  --color-dark-as-night-950: #181b1b;
}

SCSS

$dark-as-night: #495252;
$dark-as-night-rgb: 73, 82, 82;
$dark-as-night-light: mix(#fff, $dark-as-night, 20%);
$dark-as-night-dark: mix(#000, $dark-as-night, 20%);

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