#0070B9

CSS

:root {
  --french-blue: #0070b9;
  --french-blue-rgb: 0 112 185;
  --french-blue-oklch: oklch(0.532 0.142 247.6);
}

.element {
  color: var(--french-blue);
  background-color: hsl(204 100% 36%);
  border-color: oklch(0.532 0.142 247.6);
}

Tailwind CSS v4

@theme {
  --color-french-blue: #0070b9;
  --color-french-blue-50: #d7f9ff;
  --color-french-blue-100: #c4edff;
  --color-french-blue-200: #a6daff;
  --color-french-blue-300: #7dbdfd;
  --color-french-blue-400: #51a4ed;
  --color-french-blue-500: #1b8bde;
  --color-french-blue-600: #1c76bb;
  --color-french-blue-700: #165e97;
  --color-french-blue-800: #074670;
  --color-french-blue-900: #06304f;
  --color-french-blue-950: #001c34;
}

SCSS

$french-blue: #0070b9;
$french-blue-rgb: 0, 112, 185;
$french-blue-light: mix(#fff, $french-blue, 20%);
$french-blue-dark: mix(#000, $french-blue, 20%);

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