#3A7E9A

CSS

:root {
  --ahoy-blue: #3a7e9a;
  --ahoy-blue-rgb: 58 126 154;
  --ahoy-blue-oklch: oklch(0.561 0.081 227.8);
}

.element {
  color: var(--ahoy-blue);
  background-color: hsl(198 45% 42%);
  border-color: oklch(0.561 0.081 227.8);
}

Tailwind CSS v4

@theme {
  --color-ahoy-blue: #3a7e9a;
  --color-ahoy-blue-50: #dffaff;
  --color-ahoy-blue-100: #cdeefe;
  --color-ahoy-blue-200: #b2dbf0;
  --color-ahoy-blue-300: #8cc0d9;
  --color-ahoy-blue-400: #69a8c4;
  --color-ahoy-blue-500: #4491b0;
  --color-ahoy-blue-600: #3b7a95;
  --color-ahoy-blue-700: #2f6277;
  --color-ahoy-blue-800: #1f4858;
  --color-ahoy-blue-900: #15323d;
  --color-ahoy-blue-950: #061e27;
}

SCSS

$ahoy-blue: #3a7e9a;
$ahoy-blue-rgb: 58, 126, 154;
$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);
}