Blueprint

CSS

:root {
  --blueprint: #35637c;
  --blueprint-rgb: 53 99 124;
  --blueprint-oklch: oklch(0.478 0.065 234.1);
}

.element {
  color: var(--blueprint);
  background-color: hsl(201 40% 35%);
  border-color: oklch(0.478 0.065 234.1);
}

Tailwind CSS v4

@theme {
  --color-blueprint: #35637c;
  --color-blueprint-50: #e4f9ff;
  --color-blueprint-100: #d4ecfb;
  --color-blueprint-200: #bbd9ed;
  --color-blueprint-300: #98bdd5;
  --color-blueprint-400: #78a5bf;
  --color-blueprint-500: #598eab;
  --color-blueprint-600: #4c7890;
  --color-blueprint-700: #3d6074;
  --color-blueprint-800: #2a4655;
  --color-blueprint-900: #1d313b;
  --color-blueprint-950: #0c1d25;
}

SCSS

$blueprint: #35637c;
$blueprint-rgb: 53, 99, 124;
$blueprint-light: mix(#fff, $blueprint, 20%);
$blueprint-dark: mix(#000, $blueprint, 20%);

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