Heavy Blue Grey

CSS

:root {
  --heavy-blue-grey: #9fabaf;
  --heavy-blue-grey-rgb: 159 171 175;
  --heavy-blue-grey-oklch: oklch(0.733 0.015 219.7);
}

.element {
  color: var(--heavy-blue-grey);
  background-color: hsl(195 9% 65%);
  border-color: oklch(0.733 0.015 219.7);
}

Tailwind CSS v4

@theme {
  --color-heavy-blue-grey: #9fabaf;
  --color-heavy-blue-grey-50: #f1f6f8;
  --color-heavy-blue-grey-100: #e3e9eb;
  --color-heavy-blue-grey-200: #ced6d9;
  --color-heavy-blue-grey-300: #b0b9bd;
  --color-heavy-blue-grey-400: #95a1a4;
  --color-heavy-blue-grey-500: #7c898d;
  --color-heavy-blue-grey-600: #697477;
  --color-heavy-blue-grey-700: #545c5f;
  --color-heavy-blue-grey-800: #3d4446;
  --color-heavy-blue-grey-900: #2a2f30;
  --color-heavy-blue-grey-950: #171b1c;
}

SCSS

$heavy-blue-grey: #9fabaf;
$heavy-blue-grey-rgb: 159, 171, 175;
$heavy-blue-grey-light: mix(#fff, $heavy-blue-grey, 20%);
$heavy-blue-grey-dark: mix(#000, $heavy-blue-grey, 20%);

.element {
  color: $heavy-blue-grey;
  box-shadow: 0 0 0 2px rgba($heavy-blue-grey, 0.35);
}