#437CA0

CSS

:root {
  --zenith: #437ca0;
  --zenith-rgb: 67 124 160;
  --zenith-oklch: oklch(0.563 0.082 238.3);
}

.element {
  color: var(--zenith);
  background-color: hsl(203 41% 45%);
  border-color: oklch(0.563 0.082 238.3);
}

Tailwind CSS v4

@theme {
  --color-zenith: #437ca0;
  --color-zenith-50: #e1f9ff;
  --color-zenith-100: #d0ecff;
  --color-zenith-200: #b6daf4;
  --color-zenith-300: #92bede;
  --color-zenith-400: #6fa6ca;
  --color-zenith-500: #4e8eb6;
  --color-zenith-600: #43789a;
  --color-zenith-700: #35607c;
  --color-zenith-800: #24475b;
  --color-zenith-900: #183140;
  --color-zenith-950: #081d29;
}

SCSS

$zenith: #437ca0;
$zenith-rgb: 67, 124, 160;
$zenith-light: mix(#fff, $zenith, 20%);
$zenith-dark: mix(#000, $zenith, 20%);

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