#145389

CSS

:root {
  --dark-denim: #145389;
  --dark-denim-rgb: 20 83 137;
  --dark-denim-oklch: oklch(0.433 0.108 249.5);
}

.element {
  color: var(--dark-denim);
  background-color: hsl(208 75% 31%);
  border-color: oklch(0.433 0.108 249.5);
}

Tailwind CSS v4

@theme {
  --color-dark-denim: #145389;
  --color-dark-denim-50: #dff8ff;
  --color-dark-denim-100: #ceebff;
  --color-dark-denim-200: #b3d8ff;
  --color-dark-denim-300: #8ebcee;
  --color-dark-denim-400: #6ba3dc;
  --color-dark-denim-500: #488acb;
  --color-dark-denim-600: #3e75ab;
  --color-dark-denim-700: #315e89;
  --color-dark-denim-800: #204566;
  --color-dark-denim-900: #153047;
  --color-dark-denim-950: #061c2f;
}

SCSS

$dark-denim: #145389;
$dark-denim-rgb: 20, 83, 137;
$dark-denim-light: mix(#fff, $dark-denim, 20%);
$dark-denim-dark: mix(#000, $dark-denim, 20%);

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