#297BAE

CSS

:root {
  --honolulu-blue: #297bae;
  --honolulu-blue-rgb: 41 123 174;
  --honolulu-blue-oklch: oklch(0.558 0.11 240.7);
}

.element {
  color: var(--honolulu-blue);
  background-color: hsl(203 62% 42%);
  border-color: oklch(0.558 0.11 240.7);
}

Tailwind CSS v4

@theme {
  --color-honolulu-blue: #297bae;
  --color-honolulu-blue-50: #dbfaff;
  --color-honolulu-blue-100: #c9edff;
  --color-honolulu-blue-200: #abdbff;
  --color-honolulu-blue-300: #85bfec;
  --color-honolulu-blue-400: #5da7d9;
  --color-honolulu-blue-500: #328ec8;
  --color-honolulu-blue-600: #2d78a9;
  --color-honolulu-blue-700: #246087;
  --color-honolulu-blue-800: #154764;
  --color-honolulu-blue-900: #0e3146;
  --color-honolulu-blue-950: #011d2e;
}

SCSS

$honolulu-blue: #297bae;
$honolulu-blue-rgb: 41, 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);
}