Dark Blue

CSS

:root {
  --dark-blue: #315b7d;
  --dark-blue-rgb: 49 91 125;
  --dark-blue-oklch: oklch(0.456 0.073 244.8);
}

.element {
  color: var(--dark-blue);
  background-color: hsl(207 44% 34%);
  border-color: oklch(0.456 0.073 244.8);
}

Tailwind CSS v4

@theme {
  --color-dark-blue: #315b7d;
  --color-dark-blue-50: #e5f8ff;
  --color-dark-blue-100: #d5ebff;
  --color-dark-blue-200: #bcd8f2;
  --color-dark-blue-300: #9abcdb;
  --color-dark-blue-400: #7aa4c7;
  --color-dark-blue-500: #5b8bb4;
  --color-dark-blue-600: #4e7698;
  --color-dark-blue-700: #3e5e7a;
  --color-dark-blue-800: #2b455a;
  --color-dark-blue-900: #1d303f;
  --color-dark-blue-950: #0d1c28;
}

SCSS

$dark-blue: #315b7d;
$dark-blue-rgb: 49, 91, 125;
$dark-blue-light: mix(#fff, $dark-blue, 20%);
$dark-blue-dark: mix(#000, $dark-blue, 20%);

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