#137BB4

CSS

:root {
  --honolulu-blue: #137bb4;
  --honolulu-blue-rgb: 19 123 180;
  --honolulu-blue-oklch: oklch(0.557 0.123 240.5);
}

.element {
  color: var(--honolulu-blue);
  background-color: hsl(201 81% 39%);
  border-color: oklch(0.557 0.123 240.5);
}

Tailwind CSS v4

@theme {
  --color-honolulu-blue: #137bb4;
  --color-honolulu-blue-50: #d8faff;
  --color-honolulu-blue-100: #c5eeff;
  --color-honolulu-blue-200: #a6dbff;
  --color-honolulu-blue-300: #7dbff1;
  --color-honolulu-blue-400: #52a7e0;
  --color-honolulu-blue-500: #1c8fcf;
  --color-honolulu-blue-600: #1c79af;
  --color-honolulu-blue-700: #17618c;
  --color-honolulu-blue-800: #094768;
  --color-honolulu-blue-900: #063149;
  --color-honolulu-blue-950: #001d30;
}

SCSS

$honolulu-blue: #137bb4;
$honolulu-blue-rgb: 19, 123, 180;
$honolulu-blue-light: mix(#fff, $honolulu-blue, 20%);
$honolulu-blue-dark: mix(#000, $honolulu-blue, 20%);

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