#2F6FAB

CSS

:root {
  --muted-blue: #2f6fab;
  --muted-blue-rgb: 47 111 171;
  --muted-blue-oklch: oklch(0.529 0.115 249.7);
}

.element {
  color: var(--muted-blue);
  background-color: hsl(209 57% 43%);
  border-color: oklch(0.529 0.115 249.7);
}

Tailwind CSS v4

@theme {
  --color-muted-blue: #2f6fab;
  --color-muted-blue-50: #def8ff;
  --color-muted-blue-100: #cdebff;
  --color-muted-blue-200: #b1d8ff;
  --color-muted-blue-300: #8cbcf1;
  --color-muted-blue-400: #67a3e0;
  --color-muted-blue-500: #438acf;
  --color-muted-blue-600: #3a75af;
  --color-muted-blue-700: #2e5e8c;
  --color-muted-blue-800: #1d4568;
  --color-muted-blue-900: #133049;
  --color-muted-blue-950: #051c30;
}

SCSS

$muted-blue: #2f6fab;
$muted-blue-rgb: 47, 111, 171;
$muted-blue-light: mix(#fff, $muted-blue, 20%);
$muted-blue-dark: mix(#000, $muted-blue, 20%);

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