#287BAE

CSS

:root {
  --honolulu-blue: #287bae;
  --honolulu-blue-rgb: 40 123 174;
  --honolulu-blue-oklch: oklch(0.558 0.111 240.5);
}

.element {
  color: var(--honolulu-blue);
  background-color: hsl(203 63% 42%);
  border-color: oklch(0.558 0.111 240.5);
}

Tailwind CSS v4

@theme {
  --color-honolulu-blue: #287bae;
  --color-honolulu-blue-50: #dbfaff;
  --color-honolulu-blue-100: #c9edff;
  --color-honolulu-blue-200: #abdbff;
  --color-honolulu-blue-300: #84bfec;
  --color-honolulu-blue-400: #5da7d9;
  --color-honolulu-blue-500: #318ec8;
  --color-honolulu-blue-600: #2c79a9;
  --color-honolulu-blue-700: #236087;
  --color-honolulu-blue-800: #154764;
  --color-honolulu-blue-900: #0d3146;
  --color-honolulu-blue-950: #011d2e;
}

SCSS

$honolulu-blue: #287bae;
$honolulu-blue-rgb: 40, 123, 174;
$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);
}