#426F9E

CSS

:root {
  --naval: #426f9e;
  --naval-rgb: 66 111 158;
  --naval-oklch: oklch(0.53 0.09 250.8);
}

.element {
  color: var(--naval);
  background-color: hsl(211 41% 44%);
  border-color: oklch(0.53 0.09 250.8);
}

Tailwind CSS v4

@theme {
  --color-naval: #426f9e;
  --color-naval-50: #e4f7ff;
  --color-naval-100: #d3eaff;
  --color-naval-200: #bad7fa;
  --color-naval-300: #97bbe5;
  --color-naval-400: #76a2d2;
  --color-naval-500: #578ac0;
  --color-naval-600: #4a75a2;
  --color-naval-700: #3b5d82;
  --color-naval-800: #284560;
  --color-naval-900: #1b3043;
  --color-naval-950: #0b1c2b;
}

SCSS

$naval: #426f9e;
$naval-rgb: 66, 111, 158;
$naval-light: mix(#fff, $naval, 20%);
$naval-dark: mix(#000, $naval, 20%);

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