#297F9D

CSS

:root {
  --ahoy-blue: #297f9d;
  --ahoy-blue-rgb: 41 127 157;
  --ahoy-blue-oklch: oklch(0.559 0.092 225.6);
}

.element {
  color: var(--ahoy-blue);
  background-color: hsl(196 59% 39%);
  border-color: oklch(0.559 0.092 225.6);
}

Tailwind CSS v4

@theme {
  --color-ahoy-blue: #297f9d;
  --color-ahoy-blue-50: #dbfbff;
  --color-ahoy-blue-100: #c9efff;
  --color-ahoy-blue-200: #acddf3;
  --color-ahoy-blue-300: #84c1dc;
  --color-ahoy-blue-400: #5eaac8;
  --color-ahoy-blue-500: #3292b4;
  --color-ahoy-blue-600: #2c7c98;
  --color-ahoy-blue-700: #23637a;
  --color-ahoy-blue-800: #16495a;
  --color-ahoy-blue-900: #0e333f;
  --color-ahoy-blue-950: #021e28;
}

SCSS

$ahoy-blue: #297f9d;
$ahoy-blue-rgb: 41, 127, 157;
$ahoy-blue-light: mix(#fff, $ahoy-blue, 20%);
$ahoy-blue-dark: mix(#000, $ahoy-blue, 20%);

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