#11456B

CSS

:root {
  --mermaid-blues: #11456b;
  --mermaid-blues-rgb: 17 69 107;
  --mermaid-blues-oklch: oklch(0.377 0.084 245.3);
}

.element {
  color: var(--mermaid-blues);
  background-color: hsl(205 73% 24%);
  border-color: oklch(0.377 0.084 245.3);
}

Tailwind CSS v4

@theme {
  --color-mermaid-blues: #11456b;
  --color-mermaid-blues-50: #e3f8ff;
  --color-mermaid-blues-100: #d2ebff;
  --color-mermaid-blues-200: #b8d8f7;
  --color-mermaid-blues-300: #95bce1;
  --color-mermaid-blues-400: #74a4cd;
  --color-mermaid-blues-500: #548cba;
  --color-mermaid-blues-600: #48769d;
  --color-mermaid-blues-700: #395f7e;
  --color-mermaid-blues-800: #27465d;
  --color-mermaid-blues-900: #1a3041;
  --color-mermaid-blues-950: #0a1c2a;
}

SCSS

$mermaid-blues: #11456b;
$mermaid-blues-rgb: 17, 69, 107;
$mermaid-blues-light: mix(#fff, $mermaid-blues, 20%);
$mermaid-blues-dark: mix(#000, $mermaid-blues, 20%);

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