#307DAD

CSS

:root {
  --mediterranean-blue: #307dad;
  --mediterranean-blue-rgb: 48 125 173;
  --mediterranean-blue-oklch: oklch(0.564 0.105 240);
}

.element {
  color: var(--mediterranean-blue);
  background-color: hsl(203 57% 43%);
  border-color: oklch(0.564 0.105 240);
}

Tailwind CSS v4

@theme {
  --color-mediterranean-blue: #307dad;
  --color-mediterranean-blue-50: #dcfaff;
  --color-mediterranean-blue-100: #caedff;
  --color-mediterranean-blue-200: #addbfe;
  --color-mediterranean-blue-300: #87bee9;
  --color-mediterranean-blue-400: #60a7d6;
  --color-mediterranean-blue-500: #388ec4;
  --color-mediterranean-blue-600: #3179a6;
  --color-mediterranean-blue-700: #276085;
  --color-mediterranean-blue-800: #184762;
  --color-mediterranean-blue-900: #103145;
  --color-mediterranean-blue-950: #031d2d;
}

SCSS

$mediterranean-blue: #307dad;
$mediterranean-blue-rgb: 48, 125, 173;
$mediterranean-blue-light: mix(#fff, $mediterranean-blue, 20%);
$mediterranean-blue-dark: mix(#000, $mediterranean-blue, 20%);

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